Bondtech Prusa Combined for Creality Carriage

Based on the work of MaracMB, recreated his idea over the design of whitedrag0n.

- removed the Bondtech door hinge to make it easier for FDM
- added sacrificial layers under overhanging holes
- remove bottom left fan mounting hole as it interfered with the bottom Creality roller nut

**Things to do**
- Cable management: there is currently no where to route the cables past the metal mounting plate