Update .CONTRIBUTING.md

Co-authored-by: Erin Shaben <[email protected]>

Author: brunopgalvao

.CONTRIBUTING.md

@@ -90,7 +90,7 @@ Before making contributions, you need to set up the proper directory structure f
    - Follow the [PaperMoon Style Guide](https://github.com/papermoonio/documentation-style-guide).
    - Test your changes locally (see [Run Polkadot Docs Locally](../README.md#run-polkadot-docs-locally)).
 
-2. **Update AI Documentation**
+2. Update AI documentation:
 
    After making content changes, regenerate the AI-ready documentation files.