Update README.md

Author: annieappflowy

README.md

@@ -56,7 +56,7 @@ Please see the [changelog](https://www.appflowy.io/whatsnew) for more details ab
 
 ## Contributing
 
-Contributions are what make the open source community such an amazing place to be learn, inspire, and create. Any contributions you make are **greatly appreciated**. Please look at [CONTRIBUTING.md](https://github.com/AppFlowy-IO/appflowy/blob/main/doc/CONTRIBUTING.md) for details.
+Contributions are what make the open source community such an amazing place to be learn, inspire, and create. Any contributions you make are **greatly appreciated**. Please look at [Contributing to AppFlowy](https://appflowy.gitbook.io/docs/essential-documentation/contribute-to-appflowy/contributing-to-appflowy) for details.
 
 If your Pull Request is accepted as it fixes a bug, adds functionality, or makes AppFlowy's codebase significantly easier to use or understand, congratulations! If your administrative and managerial work behind the scenes that sustains the community as a whole, congratulations! You are now an official contributor to AppFlowy. Get in touch with us ([link](https://tally.so/r/mKP5z3)) to receive the very special Contributor T-shirt!
 Proudly wear your T-shirt and show it to us by tagging [@appflowy](https://twitter.com/appflowy) on Twitter.