1. Flash led on ~Ln keypress (for now it works only on +Ln)
2. Flash NumLock led only when "numpad" layer is active
3. Command (in terms of IS_COMMAND) to switch to no-leds mode
4. Increase count of ACTION keys
5. Check how it works with ACTION/TAP keys (layerN+key or modifier+key)
6. Fix command_state() onboard led:
    it should flash only when kbd in some specific mode (CONSOLE || MOUSE)
7. Fix Right TEENSY key (for now it locks kbd & system)
8. Cleanup everything, add conditionals (ifdef/ifndef), push to github