D9 X Axis Idler Bracket, works on stock printer or with MGN12 Rails

First run of a bracket that allows you to have a much more stable X Axis idler held from top and bottom.

This bracket also allows tension adjustment of the X axis belt via M3 screws on the side

Uses a long M5 bolt to hold the idler in

I've been using this for a few months now on my own printer

Will be updating it when I get time, as I’ve also an c axis stepper bracket in design that puts the belt parallel to the extrusion. The stock is about 2mm out of level on one side!