Add comprehensive skill for developing, testing, and debugging Tampermonkey userscripts with:
- Three professional templates (basic, advanced, SPA-compatible)
- Script generation and validation tools
- Modern JavaScript patterns and best practices
- DOM manipulation utilities and examples
- API integration helpers
- Complete YouTube bookmark example
- Security and performance checks
Perfect for JavaScript/browser automation developers working with Tampermonkey, Greasemonkey, or userscripts.