Voron 0.1 belted z bed mount

This originated from originally making a voron 0, with a belted z from (https://github.com/theFPVgeek/VoronUsers/tree/master/printer_mods/theFPVgeek/v0-zbelt-mod),  and having issues with inconsistent extruder I decided to convert it to a V0.1 (only the necessary parts regarding the extruder and stepper motors).

This required a new belted z bed mount as the extruder is moved 3 mm towards the printer door, therefore, this part where I extended the part connecting to the bed beams.

To implement this I removed the back panel, as when doing the original mod.