Case for PicoPSU with OpenSCAD code

Two-part case for a PicoPSU power supply. This is designed for the picoPSU-160-XT, but it looks like it will also work for the picoPSU-120 and picoPSU-80 as well.

Two STL models are included:
* One for M2 (~2.5mm) screws
* One for 3.5mm screws

If you need a different size of screw hole, download the OpenSCAD code and change the `screw_hole_diameter` variable.

I printed this with PLA and it fits around the PSU with a little play, but be aware of the shrinkage of your filament.

Print one of each `side_a_[size].stl` and `side_b_[size].stl`, where "size" is the size of the screw holes you want.

OpenSCAD code [is available on Github](https://github.com/xunker/pico_psu_case).