Customizable #gridfinity basic container for Zach Freedman's gridfinity system

The OpenScad that drives this is a minor modification of vector76'es original, basically just putting it all in one file and making the configuration a bit easier.

These containers differ from Zach Freedman's containers in that:

• Holes for magnets are optional
• The shelf for a label is optional
• The finger slide at the bottom is optional
• Magnet holes end in a cone, reducing issues with sagging over the magnet holes
• Magnet holes are sized to 6.1mm so a 6mm magnet should press-fit into the hole without needing glue (you can tune this in the customizer)

Attached STL files are examples, you should open in customizer to create your own