Ender 3 - Adjustable Endstop (full range)

I love what [Mach_Zero](https://www.thingiverse.com/Mach_Zero) designed, however the only M3 screws I have are stubby.

Here's a small remix of the mount that allows for full range of the screw. This was accomplished by cutting off the mount at the "Extra Clearance" endstop slider distance of 30mm as well as cutting off the extra height above the rail screw (to allow for clearance of the rail wheel).