chore: add repository moved warning to the readme

Author: sebcrozet

README.md

@@ -1,38 +1,6 @@
 # Website
 
-This website is built using [Docusaurus 3](https://docusaurus.io/), a modern static website generator.
-
-### Installation
-
-```sh
-$ yarn
-```
-
-### Build
-
-```sh
-$ ./generate_user_guides.sh
-```
-
-Above command reads the templates directory and extracts specific instructions for bevy / rust / rapier integrations.
-It also injects code contained in the example files.
-
-```sh
-$ yarn build
-```
-
-Above command generates static content into the `build` directory and can be served using any static contents hosting service.
-
-```sh
-$ yarn start
-```
-
-Above command builds and starts a local development server and open up a browser window. Most changes are reflected live without having to restart the server.
-
-### Deployment
-
-```sh
-$ GIT_USER=<Your GitHub username> USE_SSH=true yarn deploy
-```
-
-If you are using GitHub pages for hosting, this command is a convenient way to build the website and push to the `gh-pages` branch.
+> [!CAUTION]
+> This repository is now merged into the main [rapier repository](https://github.com/dimforge/rapier) to make it easier
+> to keep the website up-to-date with the library. Therefore, this repository is now archived so new issues and
+> pull-request must be opened on the [rapier repository](https://github.com/dimforge/rapier) instead.