* docs: improve PuterAI module documentation structure
- Update docmeta.md to describe top-level doc structure\n- Create README.md for PuterAI module documentation\n- Move requests.md content to api_examples.md\n- Add ai_usage_testing.md in contributors directory\n\nCloses #1215\n\nai: true
* docs: remove original requests.md after content migration
Content has been migrated to api_examples.md with improved organization and structure.\n\nai: true