The default keymap for KBD66

This is a fairly universal layout that supports standard ANSI, split backspace, split left shift, and split right shift.
Cycle backlight: Fn + .
Backlight breathing: Fn + ,
Volume Up/Down: Fn + [ and Fn + ]
Mute: Fn + \
Sleep: Fn + /
Bootloader Mode: Fn + CapsLock