* handwired/atreus50: refactor
- layout macro renames:
- KEYMAP is now LAYOUT
- COMPACT_KEYMAP is now LAYOUT_kc
- keymap updates:
- both keymaps now use #include QMK_KEYBOARD_H
- removed redundant KC_TRNS and KC_NO definitions
- default keymap now uses LAYOUT macro instead of LAYOUT_kc
* handwired/atreus50: readme cleanup
Reformatted the readme to be more closely aligned to current QMK
template, and fixed some typos/grammar.
* handwired/atreus50: Configurator support
