PCB din clip v2

Updated f1oat's version of the PCB DIN mount to add stuff I wanted.

Many more variables, cylindrical standoffs

I didn't enable Customizer cause I'm not sure it'd work with the changes I made & it never works anyway

The variables in the SCAD file and the STL included are a mount for the Duet 2 Ethernet/Wifi with M3 screws.