Screw GPU Support

There's only a certain amount of range that this has, but it worked for my purpose.

The screw is from a thingi that no longer exists (a Kant Twist Clamp if you were curious), even the youtube video from the readme is gone, so the internet can forget.

I remixed the nut to have more range and a surface for the GPU to rest on.

A support column looks awesome, but doesn't have flexibility.