4-finger keyboard case

I designed this case for my 4-finger keyboard based on the Kee4(tm) keyboard by Citta Consulting Inc. (http://kee4.com). For more information, see [my blog post](http://projects.stuartm.me.uk/2019/01/06/four-finger-keyboard.html).

I used [Thing:2783650](https://www.thingiverse.com/thing:2783650) (dsa button-type) for the keycaps.

I added a key frame to go over the switches. It clips onto the PCB and fixes the switches more securely.