20 mm 90 deg heat bed cable cover for Prusa Mk3

As a lot of other people, I'm going to have little space along the y axis, therefore I needed a 90° cable cover. After printing MIKEYMCC's large version (to have some space for those crimp terminals), I actually measured the necessary y space for the first time, and found that that cover would still be too large by about 15 mm. So I had to start designing my own. Big thanks to MIKEYMCC for providing the .step file

In the suspect's lineup in the pictures, from left to right:
- Prusa original