jimmy 02db2b629c Add frontend API documentation ...

- Document ESPNow message format
- Explain preset structure and parameters
- Document select format with list and step support
- Explain beat functionality and synchronization
- Include examples and best practices

2026-01-27 00:47:00 +13:00

..

API.md

Add frontend API documentation

2026-01-27 00:47:00 +13:00