P4 Matrix Stand

I wanted a stand to hold 2 Adafruit P4 32x64 matrices together along with their diffusion panel.

I whipped this up pretty quickly. I was originally hoping to allow for n number to be chained, but you would need to cut the middle diffusion panels to be the same width as the matrix.

Was debating about adding a version with tilt and places for mounting a pi and/or covers on the back.

Adafruit Parts for this are here:
[P4 64x32 Matrix](https://www.adafruit.com/product/2278)
[Diffuser Panel](https://www.adafruit.com/product/4749)