Accessing files from the action repository in a GitHub Composite Action

When building GitHub Composite Actions, the working directory defaults to the caller's repository, not the action's own repository. To reference files bundled with the action (like shell scripts), use the `github.action_path` context variable, which resolves to the directory where the action itself is located. A short `action.yml` example demonstrates running a script using `${{ github.action_path }}/script.sh`.