keyboard: add WIP R-2D version, atmega RC notes

...2-keyboard-fw/m32u4-rc/ATMega32U4-usbdevice_dfu-1_0_0.hex

reform2-keyboard-fw/m32u4-rc/Caterina-Genuino-Micro.hex

reform2-keyboard-fw/m32u4-rc/RC-NOTES.md

reform2-keyboard-fw/m32u4-rc/flash.sh

reform2-keyboard-pcb/footprints/HRO_TYPE-C-31-M-12.kicad_mod

...ard-pcb/footprints/mnt-reform-keyboard-r2-badge.kicad_mod

reform2-keyboard-pcb/keyswitches.pretty/PG1350.kicad_mod

reform2-keyboard-pcb/reform2-keyboard-backlight.sch

reform2-keyboard-pcb/reform2-keyboard-cache.lib

reform2-keyboard-pcb/reform2-keyboard.csv

reform2-keyboard-pcb/reform2-keyboard.kicad_pcb

reform2-keyboard-pcb/reform2-keyboard.kicad_pro

reform2-keyboard-pcb/reform2-keyboard.xml