Added Cursor implementation in the 'PAX-Timestamp48' folder

[PavelValentov]

🎯 Features

• UUIDv7 Compatible: Generates RFC 9562 compliant 48-bit timestamps
• Base64URL Encoding: RFC 4648 URL-safe encoding without padding
• High Performance: 5,000+ operations per second
• Monotonic Timestamps: Guaranteed ordering even in high-frequency scenarios
• Zero Dependencies: Uses only Node.js built-in modules
• TypeScript Support: Complete type definitions included
• Cross-platform: Works on Windows, macOS, and Linux
• Professional Quality: Comprehensive test suite and documentation

It took 40 minutes to create the solution from setting up the problem, to saving the documentation file.