Add LynxPrompt to Project Documentation

[GeiserX]

Summary

• Adds LynxPrompt to the Project Documentation section in alphabetical order
• LynxPrompt is a self-hostable AI config management platform for teams that manages AGENTS.md, CLAUDE.md, .cursor/rules/, slash commands, and 30+ formats
• Built with Next.js and PostgreSQL, licensed under GPL-3.0

Checklist

• Entry added in alphabetical order
• Format matches existing entries (name, link, em-dash, description)
• Description is concise and accurate