Sönke Hahn's Neo layout for the Moonlander keyboard

This is my personal keyboard layout based on the Neo keyboard layout: https://en.wikipedia.org/wiki/Neo_(keyboard_layout) This layout is not meant as a general layout for other people using the Neo keyboard layout. It's very specific to my personal needs. It still might be useful as inspiration to other people who want to create a Neo layout.

Some notes:

• I've put the ctrl key, the shift keys and the modifiers to switch to layer 4 in the middle to be operated by the thumbs. I wanted to avoid having to use my pinkies on the outer rows of the keyboard.
• The umlauts (äöü) and the ß only work on linux when configuring the compose key properly. See compose_key in ./keymap.c.