docs: simplify README to essential information only

- Reduce from 430 to 28 lines (~400 characters of content)
- Keep only critical information: installation, contents, license
- Remove verbose technical details and troubleshooting
- Make it more readable and user-friendly

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jorikfon