DOCS: Add relevant documentation for new input variables

Author: HarshCasper

README.md

@@ -15,7 +15,7 @@ To get started, you can use this minimal example:
 
 ```yml
 - name: Start LocalStack
-  uses: HarshCasper/[email protected].1
+  uses: HarshCasper/[email protected].2
   with:
     image-tag: 'latest'
     install-awslocal: 'true'
@@ -25,10 +25,14 @@ To get started, you can use this minimal example:
 
 ### Inputs
 
-|Input|Description  |Default
-|--|--|--|
-|`image-tag`  |Tag of the LocalStack Docker image to use  |`latest`
-|`install-awslocal`  |Whether to install the `awslocal` CLI into the build environment  | `true`
+| Input              | Description                                                                      | Default  |
+| ------------------ | -------------------------------------------------------------------------------- | -------- |
+| `image-tag`        | Tag of the LocalStack Docker image to use                                        | `latest` |
+| `install-awslocal` | Whether to install the `awslocal` CLI into the build environment                 | `true`   |
+| `configuration`    | Configuration variables to use while starting LocalStack container               | `None`   |
+| `use-pro`          | Whether to use the Pro version of LocalStack (requires API key to be configured) | `false`  |
+
+> **NOTE**: The `LOCALSTACK_API_KEY` environment variable is required to be set if `use-pro` is set to `true`. While starting the [localstack-pro](https://hub.docker.com/r/localstack/localstack-pro) image, the DNS startup is skipped with `DNS_ADDRESS=0` configuration variable. It is required to properly start LocalStack in GitHub Actions runner environment.
 
 ### Example workflow
 
@@ -44,10 +48,12 @@ jobs:
       - uses: actions/checkout@v3
 
       - name: Start LocalStack
-        uses: HarshCasper/[email protected].1
+        uses: HarshCasper/[email protected].2
         with:
           image-tag: 'latest'
           install-awslocal: 'true'
+          configuration: DEBUG=1
+          use-pro: 'true'
         env:
           LOCALSTACK_API_KEY: ${{ secrets.LOCALSTACK_API_KEY }}