Improved Door for Raspberry Pi Zero on Prusa i3 MK3

On my print of the original part, the latch was too deep and crashed into the Einsy when trying to close the door.

This version has been reworked with a flatter latching mechanism that is also sturdier and more printer-friendly, with the spring section being a longer horizontal bar.

The enclosure is unchanged. Only included to make downloading easier.

UPDATE 2018-08-17
Shortened the hinge length by 4mm to ensure it clears the Einsy USB port completely. Best printed in PETG for maximum