Document process for adding docs (#414)

* Document process for adding docs

* Reword

Author: arcticfly

CONTRIBUTING.md

@@ -133,4 +133,22 @@ If you run into any issues, the training output is set to maximum verbosity. Cop
 
 ### Cleaning Up
 
+When you're done, you can tear down the cluster with:
+
+```bash
+uv run sky down art
+```
+
+### Adding Docs
+
+We use Mintlify to serve our docs. Here are the steps for adding a new page:
+1. Clone the ART repo
+2. Open the /docs directory in your CLI and IDE
+3. Run npx mintlify dev to start serving a local version of the docs in your browser
+4. Create a new .mdx file in the relevant directory
+5. Add a title and sidebar title (see other pages for examples)
+6. In docs.json, add a link to the new page within one of the `navigation`.`groups`
+7. Ensure everything works by navigating to and viewing the page in your browser
+8. Submit a PR
+
 When you're done, shut down your GPU instance (if using a cloud VM) or stop the local training process.