docs: Add link to v2

README.md

@@ -2,12 +2,15 @@
 [![release](https://img.shields.io/github/release/peaceiris/actions-gh-pages.svg)](https://github.com/peaceiris/actions-gh-pages/releases/latest)
 [![GitHub release date](https://img.shields.io/github/release-date/peaceiris/actions-gh-pages.svg)](https://github.com/peaceiris/actions-gh-pages/releases)
 ![GitHub Actions status](https://github.com/peaceiris/actions-gh-pages/workflows/docker%20image%20ci/badge.svg)
-[![Docker Hub Build Status](https://img.shields.io/docker/cloud/build/peaceiris/gh-pages.svg)](https://hub.docker.com/r/peaceiris/gh-pages)
 [![Release Feed](https://img.shields.io/badge/release-feed-yellow)](https://github.com/peaceiris/actions-gh-pages/releases.atom)
 [![Dependabot Status](https://api.dependabot.com/badges/status?host=github&repo=peaceiris/actions-gh-pages)](https://dependabot.com)
 
 <img width="400" alt="GitHub Actions for deploying to GitHub Pages with Static Site Generators" src="./images/ogp.svg">
 
+> This Action is migrating to v3 (TypeScript Action)
+>
+> The old Docker Action is [peaceiris/actions-gh-pages@v2](https://github.com/peaceiris/actions-gh-pages/tree/v2)
+
 
 
 ## GitHub Actions for GitHub Pages