CTC/Geeetech i3 Pro B laser module X carriage mount

I recently purchased a 2500mW blue diode laser for a new laser engraver I want to build. It's a clone of the [Eleksmaker 445nm 2500mW Blue Laser Module with PWM](https://amzn.to/2X1YqQU) (affiliate link).

Before diving into building my own frame, though, I wanted to test it out. So, CTC i3 Pro B to the rescue.

I modified the original X carriage STL file to add four holes for M3 screws to mount the laser directly to the X carriage, eliminating the need for brackets or adding extra weight.