chore(cloudfront): Add expanded description of webAclId parameter (#9395)

Add a detailed description of this parameter as per the existing AWS API documentation to save confusion for users

Fixes #9393 

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

Author: ReidWeb

packages/@aws-cdk/aws-cloudfront/lib/web_distribution.ts

@@ -646,7 +646,14 @@ export interface CloudFrontWebDistributionProps {
 
   /**
    * Unique identifier that specifies the AWS WAF web ACL to associate with this CloudFront distribution.
+   *
+   * To specify a web ACL created using the latest version of AWS WAF, use the ACL ARN, for example
+   * `arn:aws:wafv2:us-east-1:123456789012:global/webacl/ExampleWebACL/473e64fd-f30b-4765-81a0-62ad96dd167a`.
+   *
+   * To specify a web ACL created using AWS WAF Classic, use the ACL ID, for example `473e64fd-f30b-4765-81a0-62ad96dd167a`.
+   *
    * @see https://docs.aws.amazon.com/waf/latest/developerguide/what-is-aws-waf.html
+   * @see https://docs.aws.amazon.com/cloudfront/latest/APIReference/API_CreateDistribution.html#API_CreateDistribution_RequestParameters.
    *
    * @default - No AWS Web Application Firewall web access control list (web ACL).
    */