Add README

Author: rainboyan

README.md

@@ -1,2 +1,73 @@
-# deploy-github-pages
-Deploy Grace Guides to GitHub Pages
+# Deploy Multi-Version Documentation to GitHub Pages 🚀
+
+[![Release](https://img.shields.io/github/v/release/rainboyan/deploy-github-pages?label=Release&logo=github)](https://github.com/rainboyan/deploy-github-pages/releases/latest)
+
+
+This action is used to deploy multi-version documentation to [GitHub Pages](https://pages.github.com/).
+
+## Usage
+
+We recommend this action to be used in a dedicated job:
+
+```yaml
+jobs:
+  # Build job
+  build:
+    permissions:
+      contents: read  #  to fetch code (actions/checkout)
+    runs-on: ubuntu-latest
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: rainboyan/deploy-github-pages@v1
+        env:
+          TOKEN: ${{ secrets.GH_TOKEN }}    # GitHub Personal Access Token
+          VERSION: '1.0.0-SNAPSHOT'         # The version of the documentation
+          BRANCH: gh-pages                  # The branch to deploy
+          FOLDER: build/docs                # The directory of the generated documentation
+```
+
+Here’s the directory structure for the documentation,
+
+```bash
+.
+├── 1.0.0-SNAPSHOT
+│   ├── ..
+│   └── index.html
+├── 1.0.x
+│   ├── ..
+│   └── index.html
+├── latest
+│   ├── ..
+│   └── index.html
+├── snapshot
+│   ├── ..
+│   └── index.html
+└── README.md
+```
+
+After deployment is successful, you can access the documentation through the following links,
+
+* https://OWNER.github.io/REPO/1.0.0-SNAPSHOT/
+* https://OWNER.github.io/REPO/1.0.x/
+* https://OWNER.github.io/REPO/latest/
+* https://OWNER.github.io/REPO/snapshot/
+
+### Environment Variables 🌎
+
+| Variable | Description |
+| -------- | ----------- |
+| `TOKEN` | GitHub Personal Access Token |
+| `VERSION` | The version of the documentation, if empty it will deploy to the ROOT |
+| `BRANCH` | The branch to deploy |
+| `FOLDER` | The directory of the generated documentation |
+| `CNAME` | This will create a CNAME file |
+
+## License
+
+The scripts and documentation in this project are released under the [MIT License](LICENSE).
+
+## Links
+
+- [Grace Framework](https://github.com/graceframework/grace-framework)
+- [Grace Plugins](https://github.com/grace-plugins)