Gridfinity step drill holder

Holder for 4-20 mm, 3-12mm and 4-12mm step drill bits from [Aliexpress](https://aliexpress.com/item/1005005062982142.html).

The file "box.stl" does not work for stacking boxes since it would require it to be a bit higher, in this case, use the "stackable_box.stl" file.

"box_short.stl" is probably what you want if you don't plan on stacking bins and "box_no_hole.stl" is the same as "box.stl" but the bigger drill is not poking a hole at the bottom of the bin. God knows why I chose to do that even though it wasn't stacking anyways.