Sintron i3 X Axis End For Tension Idler

To allow for longer X travel, the tension idler fits into a cutout in the right x gantry end.
I used the tension kit by JWag but wanted to use a commercial belt idler instead of two flanged bearings, so I had to modify the tension bracket. Furthermore, the original file had the M4 tension nyloc nut slot on the downside, when the bolt of the idler was to the front, I changed to have easier installation.
Use a M5 nyloc nut and an 25mm M5 bolt with a 20teeth GT2 idler (18mm outer diameter, 9mm wi