readme update

README.md

@@ -4,7 +4,9 @@
 
 This Terraform module will create an [Amazon Elastic Container Registry](https://aws.amazon.com/ecr/) private repository for use on the Cloud Platform.
 
-If you're using GitHub as your OIDC provider, this module will automatically create the required variables for authentication in your GitHub repository.
+If you're using GitHub as your OIDC provider, this module will automatically create the required variables for authentication in your GitHub repository. By default these will be created as [repository secrets and variables](https://docs.github.com/en/actions/learn-github-actions/variables#creating-configuration-variables-for-a-repository). Optionally, you can configure the module to create the ECR secrets
+and variables in your own defined [GitHub Environments](https://docs.github.com/en/actions/learn-github-actions/variables#creating-configuration-variables-for-an-environment). This pattern is useful if you
+wish to define separate ECR repositories for different Cloud Platform environments within the same GitHub repository.
 
 If you're using CircleCI as your OIDC provider, this module will create a Kubernetes ConfigMap in your namespace with your authentication variables to use as environment variables in CircleCI.