Modified dual extruder X-carriage for Direct-drive hinged extrud

SummaryI used the original double wide X-carriage listed here, but added 1mm spacing to the screws so it matched exactly the screw spacing specifications for a Nema 17. I also added two more sets of screw holes so you can mount the motors up higher to save print height and extended the frame for them. I also added a fourth bearing spot for a theoretically smoother ride.