docs(README): add working_directory input

Author: arman1371

README.md

@@ -67,6 +67,7 @@ jobs:
 | Name                           | Description                                                                                                                                                                                                                       | Default                                                         |
 | ------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------- |
 | `github_token`                 | Token for the repo. Can be passed in using `${{ secrets.GITHUB_TOKEN }}`. Required if `push: true`                                                                                                                                | -                                                               |
+| `working_directory`            | Change to this directory before running                                                                                                                                                                                           | repo root directory                                             |
 | `dry_run`                      | Run without creating commit, output to stdout                                                                                                                                                                                     | false                                                           |
 | `repository`                   | Repository name to push. Default or empty value represents current github repository                                                                                                                                              | current one                                                     |
 | `branch`                       | Destination branch to push changes                                                                                                                                                                                                | Same as the one executing the action by default                 |