Easy Access X-Carriage Back for Bear-BMG Fusion Extruder

This is a quick remix to allow easy access to the screws that hold the motor and front cover for the Bear-BMG Fusion Extruder. This allows much faster disassembly for bad jams or motor changing when needed.

All I added was two 6mm holes right above the 50mm screws that hold the extruder together, no other changes, so it prints just like the original back.