chore(docs): Clarify the L2 Contribution Process (#20044)

Updates the language in `CONTRIBUTING.md` and in each CFN-only module's README to require all L2 implementation PRs to first have an approved RFC. This will avoid contributors having to redesign APIs after they've already implemented them in a pull request.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

CONTRIBUTING.md

@@ -228,7 +228,8 @@ sufficient to get clarity on what you plan to do. If the changes are
 significant or intrusive to the existing CDK experience, and especially for a
 brand new L2 construct implementation, please write an RFC in our [RFC
 repository](https://github.com/aws/aws-cdk-rfcs) before jumping into the code
-base.
+base. L2 construct implementation pull requests will not be reviewed without
+linking an approved RFC.
 
 ### Step 3: Work your Magic
 

packages/@aws-cdk/alexa-ask/README.md

@@ -27,6 +27,13 @@ There are no official hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/
 - Use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, in the same way you would use [the CloudFormation Alexa::ASK resources](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/Alexa_ASK.html) directly.
 
 
-(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) if you are interested in contributing to this construct library.)
+<!--BEGIN CFNONLY DISCLAIMER-->
+
+There are no hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_lib)) constructs for this service yet. 
+However, you can still use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, and use this service exactly as you would using CloudFormation directly.
+
+For more information on the resources and properties available for this service, see the [CloudFormation documentation for Alexa::ASK](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/Alexa_ASK.html).
+
+(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) and submit an RFC if you are interested in contributing to this construct library.)
 
 <!--END CFNONLY DISCLAIMER-->

packages/@aws-cdk/aws-accessanalyzer/README.md

@@ -27,6 +27,13 @@ There are no official hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/
 - Use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, in the same way you would use [the CloudFormation AWS::AccessAnalyzer resources](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AccessAnalyzer.html) directly.
 
 
-(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) if you are interested in contributing to this construct library.)
+<!--BEGIN CFNONLY DISCLAIMER-->
+
+There are no hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_lib)) constructs for this service yet. 
+However, you can still use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, and use this service exactly as you would using CloudFormation directly.
+
+For more information on the resources and properties available for this service, see the [CloudFormation documentation for AWS::AccessAnalyzer](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AccessAnalyzer.html).
+
+(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) and submit an RFC if you are interested in contributing to this construct library.)
 
 <!--END CFNONLY DISCLAIMER-->

packages/@aws-cdk/aws-amazonmq/README.md

@@ -27,6 +27,13 @@ There are no official hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/
 - Use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, in the same way you would use [the CloudFormation AWS::AmazonMQ resources](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AmazonMQ.html) directly.
 
 
-(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) if you are interested in contributing to this construct library.)
+<!--BEGIN CFNONLY DISCLAIMER-->
+
+There are no hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_lib)) constructs for this service yet. 
+However, you can still use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, and use this service exactly as you would using CloudFormation directly.
+
+For more information on the resources and properties available for this service, see the [CloudFormation documentation for AWS::AmazonMQ](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AmazonMQ.html).
+
+(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) and submit an RFC if you are interested in contributing to this construct library.)
 
 <!--END CFNONLY DISCLAIMER-->

packages/@aws-cdk/aws-amplifyuibuilder/README.md

@@ -27,6 +27,13 @@ There are no official hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/
 - Use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, in the same way you would use [the CloudFormation AWS::AmplifyUIBuilder resources](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AmplifyUIBuilder.html) directly.
 
 
-(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) if you are interested in contributing to this construct library.)
+<!--BEGIN CFNONLY DISCLAIMER-->
+
+There are no hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_lib)) constructs for this service yet. 
+However, you can still use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, and use this service exactly as you would using CloudFormation directly.
+
+For more information on the resources and properties available for this service, see the [CloudFormation documentation for AWS::AmplifyUIBuilder](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AmplifyUIBuilder.html).
+
+(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) and submit an RFC if you are interested in contributing to this construct library.)
 
 <!--END CFNONLY DISCLAIMER-->

packages/@aws-cdk/aws-appconfig/README.md

@@ -27,6 +27,13 @@ There are no official hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/
 - Use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, in the same way you would use [the CloudFormation AWS::AppConfig resources](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AppConfig.html) directly.
 
 
-(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) if you are interested in contributing to this construct library.)
+<!--BEGIN CFNONLY DISCLAIMER-->
+
+There are no hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_lib)) constructs for this service yet. 
+However, you can still use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, and use this service exactly as you would using CloudFormation directly.
+
+For more information on the resources and properties available for this service, see the [CloudFormation documentation for AWS::AppConfig](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AppConfig.html).
+
+(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) and submit an RFC if you are interested in contributing to this construct library.)
 
 <!--END CFNONLY DISCLAIMER-->

packages/@aws-cdk/aws-appflow/README.md

@@ -27,6 +27,13 @@ There are no official hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/
 - Use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, in the same way you would use [the CloudFormation AWS::AppFlow resources](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AppFlow.html) directly.
 
 
-(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) if you are interested in contributing to this construct library.)
+<!--BEGIN CFNONLY DISCLAIMER-->
+
+There are no hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_lib)) constructs for this service yet. 
+However, you can still use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, and use this service exactly as you would using CloudFormation directly.
+
+For more information on the resources and properties available for this service, see the [CloudFormation documentation for AWS::AppFlow](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AppFlow.html).
+
+(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) and submit an RFC if you are interested in contributing to this construct library.)
 
 <!--END CFNONLY DISCLAIMER-->

packages/@aws-cdk/aws-appintegrations/README.md

@@ -27,6 +27,13 @@ There are no official hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/
 - Use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, in the same way you would use [the CloudFormation AWS::AppIntegrations resources](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AppIntegrations.html) directly.
 
 
-(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) if you are interested in contributing to this construct library.)
+<!--BEGIN CFNONLY DISCLAIMER-->
+
+There are no hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_lib)) constructs for this service yet. 
+However, you can still use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, and use this service exactly as you would using CloudFormation directly.
+
+For more information on the resources and properties available for this service, see the [CloudFormation documentation for AWS::AppIntegrations](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AppIntegrations.html).
+
+(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) and submit an RFC if you are interested in contributing to this construct library.)
 
 <!--END CFNONLY DISCLAIMER-->

packages/@aws-cdk/aws-applicationinsights/README.md

@@ -27,6 +27,13 @@ There are no official hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/
 - Use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, in the same way you would use [the CloudFormation AWS::ApplicationInsights resources](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_ApplicationInsights.html) directly.
 
 
-(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) if you are interested in contributing to this construct library.)
+<!--BEGIN CFNONLY DISCLAIMER-->
+
+There are no hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_lib)) constructs for this service yet. 
+However, you can still use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, and use this service exactly as you would using CloudFormation directly.
+
+For more information on the resources and properties available for this service, see the [CloudFormation documentation for AWS::ApplicationInsights](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_ApplicationInsights.html).
+
+(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) and submit an RFC if you are interested in contributing to this construct library.)
 
 <!--END CFNONLY DISCLAIMER-->

packages/@aws-cdk/aws-appstream/README.md

@@ -27,6 +27,13 @@ There are no official hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/
 - Use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, in the same way you would use [the CloudFormation AWS::AppStream resources](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AppStream.html) directly.
 
 
-(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) if you are interested in contributing to this construct library.)
+<!--BEGIN CFNONLY DISCLAIMER-->
+
+There are no hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_lib)) constructs for this service yet. 
+However, you can still use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, and use this service exactly as you would using CloudFormation directly.
+
+For more information on the resources and properties available for this service, see the [CloudFormation documentation for AWS::AppStream](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AppStream.html).
+
+(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) and submit an RFC if you are interested in contributing to this construct library.)
 
 <!--END CFNONLY DISCLAIMER-->

packages/@aws-cdk/aws-aps/README.md

@@ -27,6 +27,13 @@ There are no official hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/
 - Use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, in the same way you would use [the CloudFormation AWS::APS resources](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_APS.html) directly.
 
 
-(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) if you are interested in contributing to this construct library.)
+<!--BEGIN CFNONLY DISCLAIMER-->
+
+There are no hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_lib)) constructs for this service yet. 
+However, you can still use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, and use this service exactly as you would using CloudFormation directly.
+
+For more information on the resources and properties available for this service, see the [CloudFormation documentation for AWS::APS](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_APS.html).
+
+(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) and submit an RFC if you are interested in contributing to this construct library.)
 
 <!--END CFNONLY DISCLAIMER-->

packages/@aws-cdk/aws-athena/README.md

@@ -27,6 +27,13 @@ There are no official hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/
 - Use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, in the same way you would use [the CloudFormation AWS::Athena resources](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_Athena.html) directly.
 
 
-(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) if you are interested in contributing to this construct library.)
+<!--BEGIN CFNONLY DISCLAIMER-->
+
+There are no hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_lib)) constructs for this service yet. 
+However, you can still use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, and use this service exactly as you would using CloudFormation directly.
+
+For more information on the resources and properties available for this service, see the [CloudFormation documentation for AWS::Athena](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_Athena.html).
+
+(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) and submit an RFC if you are interested in contributing to this construct library.)
 
 <!--END CFNONLY DISCLAIMER-->

packages/@aws-cdk/aws-auditmanager/README.md

@@ -27,6 +27,13 @@ There are no official hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/
 - Use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, in the same way you would use [the CloudFormation AWS::AuditManager resources](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AuditManager.html) directly.
 
 
-(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) if you are interested in contributing to this construct library.)
+<!--BEGIN CFNONLY DISCLAIMER-->
+
+There are no hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_lib)) constructs for this service yet. 
+However, you can still use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, and use this service exactly as you would using CloudFormation directly.
+
+For more information on the resources and properties available for this service, see the [CloudFormation documentation for AWS::AuditManager](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AuditManager.html).
+
+(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) and submit an RFC if you are interested in contributing to this construct library.)
 
 <!--END CFNONLY DISCLAIMER-->

packages/@aws-cdk/aws-autoscalingplans/README.md

@@ -27,6 +27,13 @@ There are no official hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/
 - Use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, in the same way you would use [the CloudFormation AWS::AutoScalingPlans resources](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AutoScalingPlans.html) directly.
 
 
-(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) if you are interested in contributing to this construct library.)
+<!--BEGIN CFNONLY DISCLAIMER-->
+
+There are no hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_lib)) constructs for this service yet. 
+However, you can still use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, and use this service exactly as you would using CloudFormation directly.
+
+For more information on the resources and properties available for this service, see the [CloudFormation documentation for AWS::AutoScalingPlans](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_AutoScalingPlans.html).
+
+(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) and submit an RFC if you are interested in contributing to this construct library.)
 
 <!--END CFNONLY DISCLAIMER-->

packages/@aws-cdk/aws-billingconductor/README.md

@@ -27,6 +27,13 @@ There are no official hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/
 - Use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, in the same way you would use [the CloudFormation AWS::BillingConductor resources](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_BillingConductor.html) directly.
 
 
-(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) if you are interested in contributing to this construct library.)
+<!--BEGIN CFNONLY DISCLAIMER-->
+
+There are no hand-written ([L2](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_lib)) constructs for this service yet. 
+However, you can still use the automatically generated [L1](https://docs.aws.amazon.com/cdk/latest/guide/constructs.html#constructs_l1_using) constructs, and use this service exactly as you would using CloudFormation directly.
+
+For more information on the resources and properties available for this service, see the [CloudFormation documentation for AWS::BillingConductor](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/AWS_BillingConductor.html).
+
+(Read the [CDK Contributing Guide](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md) and submit an RFC if you are interested in contributing to this construct library.)
 
 <!--END CFNONLY DISCLAIMER-->