Created npm run clone:repos script to clone required Babylon.js
repositories before indexing. Updated README to document the
two-step setup process:
1. Clone repositories
2. Index all data
This makes the setup process clearer and handles the missing
repository error users were encountering.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
