Gridfinity Thin base with magnets

This is a quick remix to add magnet holes to the thin base plates. I use these in my tool boxes. The magnets hold the base plate in pretty securely.

This uses the same size magnets as the bins: 6mm x 2mm. 

Prusa slicer handles the magnet holes well, but you need to make sure you enable bridge settings in Cura when you print these. 

Includes sizes from 2x2 up to 6x6. Let me know if you want a bigger size, but I figured 6x6 is the maximum for most printers (that's the biggest my CR-10 will do.)

30-Nov-2022: Updated based on the recent Gridfinity Rebuilt. The tops are now flat, more efficient printing.