Led panel support

Looking for some mounting for my LED panel, I found [this one](https://www.thingiverse.com/thing:3342728) here on thingiverse. But it was no good to me, sadly: my Geetech Prusa i3 printer was too small for it to fit in one piece, and that model was even smaller than my panel (mine's 225 mm).

So, I made this one support from scratch. The idea is to print 4 identical pieces, which gives you a full square.

FreeCad files are available for everybody to use as they will. You may want to add some hole there for the cable, or maybe change some size.