change README based on PR review

Author: github-actions[bot]

README.md

@@ -75,8 +75,6 @@ jobs:
     - name: Start MongoDB
       uses: step-security/[email protected]
       with:
-        # Here we are using an image from Amazon's ECR rather than the default image from Docker Hub
-        mongodb-image: 'public.ecr.aws/docker/library/mongo'
         mongodb-version: ${{ matrix.mongodb-version }}
         mongodb-replica-set: test-rs
         mongodb-port: 42069
@@ -134,6 +132,17 @@ jobs:
         CI: true
 ```
 
+### Using a Custom Mongo Image
+You can utilize an alternative Redis image using the `mongodb-image` input:
+
+```yaml
+    - name: Start MongoDB
+      uses: supercharge/[email protected]
+      with:
+        # Here we are using an image from Amazon's ECR rather than the default image from Docker Hub
+        mongodb-image: 'public.ecr.aws/docker/library/mongo'
+        mongodb-version: ${{ matrix.mongodb-version }}
+```
 
 ### With Authentication (MongoDB `--auth` Flag)
 Setting the `mongodb-username` and `mongodb-password` inputs. As per the [Dockerhub documentation](https://hub.docker.com/_/mongo), this automatically creates an admin user and enables `--auth` mode.