chore: replace env var creds example with configure-aws-credentials e…

…xample (#49)

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

README.md

@@ -41,24 +41,26 @@ See [action.yml](action.yml) for the full documentation for this action's inputs
 
 This action relies on the [default behavior of the AWS SDK for Javascript](https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/setting-credentials-node.html) to determine AWS credentials and region.  Use [the `aws-actions/configure-aws-credentials` action](https://github.com/aws-actions/configure-aws-credentials) to configure the GitHub Actions environment with environment variables containing AWS credentials and your desired region.
 
+```yaml
+    - name: Configure AWS credentials
+      uses: aws-actions/configure-aws-credentials@v1
+      with:
+        aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
+        aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
+        aws-region: us-east-2
+
+    - name: Login to Amazon ECR
+      id: login-ecr
+      uses: aws-actions/amazon-ecr-login@v1
+```
+
 We recommend following [Amazon IAM best practices](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html) for the AWS credentials used in GitHub Actions workflows, including:
 * Do not store credentials in your repository's code.  You may use [GitHub Actions secrets](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/creating-and-using-encrypted-secrets) to store credentials and redact credentials from GitHub Actions workflow logs.
 * [Create an individual IAM user](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html#create-iam-users) with an access key for use in GitHub Actions workflows, preferably one per repository. Do not use the AWS account root user access key.
 * [Grant least privilege](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html#grant-least-privilege) to the credentials used in GitHub Actions workflows.  Grant only the permissions required to perform the actions in your GitHub Actions workflows.  See the Permissions section below for the permissions required by this action.
 * [Rotate the credentials](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html#rotate-credentials) used in GitHub Actions workflows regularly.
 * [Monitor the activity](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html#keep-a-log) of the credentials used in GitHub Actions workflows.
 
-#### Example of using ENV variables stored in GitHub Secrets
-```
-- name: Login to Amazon ECR
-  id: login-ecr
-  uses: aws-actions/amazon-ecr-login@v1
-  env:
-    AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
-    AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
-    AWS_REGION: ${{ secrets.AWS_REGION }}
-```
-
 ## Permissions
 
 This action requires the following minimum set of permissions: