Low Profile Raspberry Pi Zero Case

This is a remix of the Raspberry Pi Zero Case by CO3D found here: https://www.thingiverse.com/thing:2962386

I added a top that has a cutout for a 12mm x 12mm heatsink.

I know the pi zero doesn't need it, and my 3mm tall heatsink isn't going to do
much but hey, it makes me feel better, so why not.