Update docs to add fifo_topic and content_based_deduplication for SNS…

… Topics

website/docs/r/sns_topic.html.markdown

@@ -20,7 +20,7 @@ resource "aws_sns_topic" "user_updates" {
 
 ## Example with Delivery Policy
 
-``` hcl
+```hcl
 resource "aws_sns_topic" "user_updates" {
   name = "user-updates-topic"
   delivery_policy = <<EOF
@@ -54,40 +54,52 @@ resource "aws_sns_topic" "user_updates" {
 }
 ```
 
+## Example with First-In-First-Out (FIFO)
+
+```hcl
+resource "aws_sns_topic" "user_updates" {
+  name                        = "user-updates-topic"
+  fifo_topic                  = true
+  content_based_deduplication = true
+}
+```
+
 ## Message Delivery Status Arguments
 
-The `<endpoint>_success_feedback_role_arn` and `<endpoint>_failure_feedback_role_arn` arguments are used to give Amazon SNS write access to use CloudWatch Logs on your behalf. The `<endpoint>_success_feedback_sample_rate` argument is for specifying the sample rate percentage (0-100) of successfully delivered messages. After you configure the  `<endpoint>_failure_feedback_role_arn` argument, then all failed message deliveries generate CloudWatch Logs.
+The `<endpoint>_success_feedback_role_arn` and `<endpoint>_failure_feedback_role_arn` arguments are used to give Amazon SNS write access to use CloudWatch Logs on your behalf. The `<endpoint>_success_feedback_sample_rate` argument is for specifying the sample rate percentage (0-100) of successfully delivered messages. After you configure the `<endpoint>_failure_feedback_role_arn` argument, then all failed message deliveries generate CloudWatch Logs.
 
 ## Argument Reference
 
 The following arguments are supported:
 
-* `name` - (Optional) The friendly name for the SNS topic. By default generated by Terraform.
-* `name_prefix` - (Optional) The friendly name for the SNS topic. Conflicts with `name`.
-* `display_name` - (Optional) The display name for the SNS topic
-* `policy` - (Optional) The fully-formed AWS policy as JSON. For more information about building AWS IAM policy documents with Terraform, see the [AWS IAM Policy Document Guide](https://learn.hashicorp.com/terraform/aws/iam-policy).
-* `delivery_policy` - (Optional) The SNS delivery policy. More on [AWS documentation](https://docs.aws.amazon.com/sns/latest/dg/DeliveryPolicies.html)
-* `application_success_feedback_role_arn` - (Optional) The IAM role permitted to receive success feedback for this topic
-* `application_success_feedback_sample_rate` - (Optional) Percentage of success to sample
-* `application_failure_feedback_role_arn` - (Optional) IAM role for failure feedback
-* `http_success_feedback_role_arn` - (Optional) The IAM role permitted to receive success feedback for this topic
-* `http_success_feedback_sample_rate` - (Optional) Percentage of success to sample
-* `http_failure_feedback_role_arn` - (Optional) IAM role for failure feedback
-* `kms_master_key_id` - (Optional) The ID of an AWS-managed customer master key (CMK) for Amazon SNS or a custom CMK. For more information, see [Key Terms](https://docs.aws.amazon.com/sns/latest/dg/sns-server-side-encryption.html#sse-key-terms)
-* `lambda_success_feedback_role_arn` - (Optional) The IAM role permitted to receive success feedback for this topic
-* `lambda_success_feedback_sample_rate` - (Optional) Percentage of success to sample
-* `lambda_failure_feedback_role_arn` - (Optional) IAM role for failure feedback
-* `sqs_success_feedback_role_arn` - (Optional) The IAM role permitted to receive success feedback for this topic
-* `sqs_success_feedback_sample_rate` - (Optional) Percentage of success to sample
-* `sqs_failure_feedback_role_arn` - (Optional) IAM role for failure feedback
-* `tags` - (Optional) Key-value map of resource tags
+- `name` - (Optional) The friendly name for the SNS topic. By default generated by Terraform.
+- `name_prefix` - (Optional) The friendly name for the SNS topic. Conflicts with `name`.
+- `display_name` - (Optional) The display name for the SNS topic
+- `policy` - (Optional) The fully-formed AWS policy as JSON. For more information about building AWS IAM policy documents with Terraform, see the [AWS IAM Policy Document Guide](https://learn.hashicorp.com/terraform/aws/iam-policy).
+- `delivery_policy` - (Optional) The SNS delivery policy. More on [AWS documentation](https://docs.aws.amazon.com/sns/latest/dg/DeliveryPolicies.html)
+- `application_success_feedback_role_arn` - (Optional) The IAM role permitted to receive success feedback for this topic
+- `application_success_feedback_sample_rate` - (Optional) Percentage of success to sample
+- `application_failure_feedback_role_arn` - (Optional) IAM role for failure feedback
+- `http_success_feedback_role_arn` - (Optional) The IAM role permitted to receive success feedback for this topic
+- `http_success_feedback_sample_rate` - (Optional) Percentage of success to sample
+- `http_failure_feedback_role_arn` - (Optional) IAM role for failure feedback
+- `kms_master_key_id` - (Optional) The ID of an AWS-managed customer master key (CMK) for Amazon SNS or a custom CMK. For more information, see [Key Terms](https://docs.aws.amazon.com/sns/latest/dg/sns-server-side-encryption.html#sse-key-terms)
+- `fifo_topic` - (Optional) Boolean indicating whether or not to make the topic First-In-First-Out (FIFO) (default is `false`).
+- `content_based_deduplication` - (Optional) Enables content-based deduplication for FIFO topics. For more information, see the [related documentation](https://docs.aws.amazon.com/sns/latest/dg/fifo-message-dedup.html)
+- `lambda_success_feedback_role_arn` - (Optional) The IAM role permitted to receive success feedback for this topic
+- `lambda_success_feedback_sample_rate` - (Optional) Percentage of success to sample
+- `lambda_failure_feedback_role_arn` - (Optional) IAM role for failure feedback
+- `sqs_success_feedback_role_arn` - (Optional) The IAM role permitted to receive success feedback for this topic
+- `sqs_success_feedback_sample_rate` - (Optional) Percentage of success to sample
+- `sqs_failure_feedback_role_arn` - (Optional) IAM role for failure feedback
+- `tags` - (Optional) Key-value map of resource tags
 
 ## Attributes Reference
 
 In addition to all arguments above, the following attributes are exported:
 
-* `id` - The ARN of the SNS topic
-* `arn` - The ARN of the SNS topic, as a more obvious property (clone of id)
+- `id` - The ARN of the SNS topic
+- `arn` - The ARN of the SNS topic, as a more obvious property (clone of id)
 
 ## Import