docs: simplify GitHub Actions section to avoid doc duplication

Remove inline YAML example and instead reference the official
GitHub Action repository for setup instructions. This prevents
documentation drift and ensures users always get the most
up-to-date configuration examples from the authoritative source.

Author: claude

README.md

@@ -572,37 +572,10 @@ $rules[] = Rule::allClasses()
 
 You can easily integrate PHPArkitect into your CI/CD pipeline using the official GitHub Action.
 
-Add this to your `.github/workflows/arkitect.yml`:
+For setup instructions and usage examples, please refer to the official documentation:
 
-```yaml
-name: Arkitect
-
-on:
-  pull_request:
-  push:
-    branches:
-      - main
-
-jobs:
-  arkitect:
-    runs-on: ubuntu-latest
-    name: Arkitect
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Run Arkitect
-        uses: docker://phparkitect/arkitect-github-actions
-        env:
-          PHP_VERSION: '8.2'
-        with:
-          args: check
-```
-
-**Resources:**
-- [GitHub Action Repository](https://github.com/phparkitect/arkitect-github-actions)
-- [GitHub Marketplace](https://github.com/marketplace/actions/phparkitect-arkitect)
-
-The action supports multiple PHP versions through the `PHP_VERSION` environment variable.
+- [GitHub Action Repository](https://github.com/phparkitect/arkitect-github-actions) - Complete setup guide and examples
+- [GitHub Marketplace](https://github.com/marketplace/actions/phparkitect-arkitect) - Action listing
 
 ## Laravel