Add Boost58

[Vacant0mens]

Name:  Boost58
Layout: staggered column
Features: split, encoder, fully reversible pcb
Availability: source available
Website: https://github.com/Vacant0mens/boost58_kb
Image: https://github.com/Vacant0mens/boost58_kb/blob/main/Boost58_top_layout.png

I've designed, assembled, and tested the prototype (v0.1 - current 'main' branch).
After updates to the design, I'm proud to say v0.2 is stable and ready for production.

I hope to share my creation with any many people as I can.

Also, if anyone has any feedback, questions, or comments, feel free to hit me up. 👍