Support multiple layers

Hey, I have an awesome news, I've redesigned the architecture a bit and now we can configure color layout per layer.

This is breaking change. You have to edit your keyboard's firmware again – but the good news is that now we require only the pre-installed plugins, so the newcomers should have a good time. See the documentation for more information or the example right away.

Official release

Enjoy 🚀

Don't forget to start the repository if you like it! 👍

Using https://github.com/jukben/Kaleidoscope-LEDCustomPalette as driver.