Joypad extension for improved precision (e.g. for aiming).

The individual parts have cavities for magnets (circular 8mm diameter, 2mm thickness).

joypad_magnet_top and joypad_left are meant to be glued together as well as joypad and joypad_inlay.

The completed model snaps together with the inserted magnets and allows for custom grips to be printed.

This version is a tad long so consider that before printing. I might add some shorter version in the future.