Add LocalStack for AWS license requirement (#17)

* Add LocalStack for AWS license requirement to prerequisites

* Hyperlink LOCALSTACK_AUTH_TOKEN and clean up localstack CLI prerequisite

* trigger CI

* Add auth token guard to start target

Author: HarshCasper

Makefile

@@ -62,6 +62,7 @@ run:			## Execute a SQL query through the Lambda function
 
 start:			## Start LocalStack in detached mode
 		@echo "Starting LocalStack..."
+		@test -n "${LOCALSTACK_AUTH_TOKEN}" || (echo "LOCALSTACK_AUTH_TOKEN is not set. Find your token at https://app.localstack.cloud/workspace/auth-token"; exit 1)
 		@LOCALSTACK_AUTH_TOKEN=$(LOCALSTACK_AUTH_TOKEN) localstack start -d
 		@echo "LocalStack started successfully."
 

README.md

@@ -26,7 +26,8 @@ The following diagram shows the architecture that this sample application builds
 
 ## Prerequisites
 
-- [`localstack` CLI](https://docs.localstack.cloud/getting-started/installation/#localstack-cli) with a [`LOCALSTACK_AUTH_TOKEN`](https://docs.localstack.cloud/getting-started/auth-token/).
+- A valid [LocalStack for AWS license](https://localstack.cloud/pricing). Your license provides a [`LOCALSTACK_AUTH_TOKEN`](https://docs.localstack.cloud/getting-started/auth-token/) to activate LocalStack.
+- [`localstack` CLI](https://docs.localstack.cloud/getting-started/installation/#localstack-cli).
 - [AWS CLI](https://docs.localstack.cloud/user-guide/integrations/aws-cli/) with the [`awslocal` wrapper](https://docs.localstack.cloud/user-guide/integrations/aws-cli/#localstack-aws-cli-awslocal).
 - [CDK](https://docs.localstack.cloud/user-guide/integrations/aws-cdk/) with the [`cdklocal`](https://www.npmjs.com/package/aws-cdk-local) wrapper.
 - [Node.js](https://nodejs.org/en/download/)
@@ -47,6 +48,7 @@ Then, navigate to the project directory:
 ```shell
 cd sample-cdk-rds-database-initialization
 ```
+
 Next, install the project dependencies by running the following command:
 
 ```shell