docs: Terraform reference for SAR Lambda Layer (aws-powertools#716)

Co-authored-by: heitorlessa <[email protected]>

Author: DanyC97

docs/index.md

@@ -124,6 +124,54 @@ If using SAM, you can include this SAR App as part of your shared Layers stack,
             )
     ```
 
+=== "Terraform"
+
+	> Credits to [Dani Comnea](https://github.com/DanyC97) for providing the Terraform equivalent.
+
+    ```terraform hl_lines="12-13 15-20 23-25 40"
+    terraform {
+      required_version = "~> 0.13"
+      required_providers {
+        aws = "~> 3.50.0"
+      }
+    }
+
+    provider "aws" {
+      region  = "us-east-1"
+    }
+
+    resource "aws_serverlessapplicationrepository_cloudformation_stack" "deploy_sar_stack" {
+      name = "aws-lambda-powertools-python-layer"
+
+      application_id   = data.aws_serverlessapplicationrepository_application.sar_app.application_id
+      semantic_version = data.aws_serverlessapplicationrepository_application.sar_app.semantic_version
+      capabilities = [
+        "CAPABILITY_IAM",
+        "CAPABILITY_NAMED_IAM"
+      ]
+    }
+
+    data "aws_serverlessapplicationrepository_application" "sar_app" {
+      application_id   = "arn:aws:serverlessrepo:eu-west-1:057560766410:applications/aws-lambda-powertools-python-layer"
+      semantic_version = var.aws_powertools_version
+    }
+
+    variable "aws_powertools_version" {
+      type        = string
+      default     = "1.20.2"
+      description = "The AWS Powertools release version"
+    }
+
+    output "deployed_powertools_sar_version" {
+      value = data.aws_serverlessapplicationrepository_application.sar_app.semantic_version
+    }
+
+	# Fetch Lambda Powertools Layer ARN from deployed SAR App
+	output "aws_lambda_powertools_layer_arn" {
+	  value = aws_serverlessapplicationrepository_cloudformation_stack.deploy_sar_stack.outputs.LayerVersionArn
+	}
+    ```
+
 ??? tip "Example of least-privileged IAM permissions to deploy Layer"
 
     > Credits to [mwarkentin](https://github.com/mwarkentin) for providing the scoped down IAM permissions.