* modernize acr60.h
- use #pragma once include guard
- add license header
- use four-space indent
- use QMK three-character notation for layout macro arguments
* human-friendly format info.json
* remove `key_count` keys from info.json
* rename LAYOUT_2_shifts to LAYOUT_all
* move LAYOUT_all to top
* use QMK three-character notation in info.json
* refactor default keymap
- add license header
- remove third layer (does nothing)
- replace Shift-Escape keycode with KC_GESC
- use LAYOUT_all macro instead of LAYOUT
* modernize readme.md
- update header
- convert metadata section to list
- add flashing and bootloader jump instructions
- update Docs links
* use #pragma once include guard in config.h
* update LED Indicator API
* add license headers
James Young