Graber i3 X-Endstop Holder

This part was heavily inspired by things [765805](https://www.thingiverse.com/thing:765805) and [806909](https://www.thingiverse.com/thing:806909), although I redesigned it from scratch to suit my needs.

The things above wouldn't fit my printer because the endstop sensor wouldn't be hit by the X-carriage, so I had to make it thinner and measure everything so that it would fit fine.

It is a really thin and lightweight endstop holder for Graber i3 that stays on by press fit and requires 2x M