docs: Added credential configuration

Added docs about how to configure aws credentials before deployment

README.md

@@ -5,12 +5,21 @@ This action deploys ECS services using [fabfuel/ecs-deploy](https://github.com/f
 ## Example usage
 
 ```yml
-uses: brunocascio/[email protected]
-with:
-  cluster: theClusterName
-  service: theServiceName
-  task: theTaskDefinitionName
-  container: theContainerName
-  envfile: /path/to/your/envfile (optionally)
-  timeout: 720 (optionally, default 300)
-```
+
+- 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: ${{ secrets.AWS_REGION }} 
+
+- name: Deploy to ecs
+  uses: brunocascio/[email protected]
+  with:
+    cluster: theClusterName
+    service: theServiceName
+    task: theTaskDefinitionName
+    container: theContainerName
+    envfile: /path/to/your/envfile (optionally)
+    timeout: 720 (optionally, default 300)
+```