Update X-Axis bracket for Articulating Raspberry Pi Camera Mount

This is a remix for X-Bracket, so it fits with the MK3S belt tensioning system (the stepper motor can be moved up-down in order to tighten/loosen the X axis belt).

It also adds two additional holes to use zip-ties to strain relief or tie cables that are passing around (such as the X-Axis stepper motor cable).