Add Vizio diagram source files to this repository

[dthaler]

I think the original diagrams might have been drawn with Visio and are saved in Microsoft Teams. But I am no longer in the Microsoft tenant so I can't access the channel to check.

Originally posted by @micya in #281 (comment)

[dthaler]

Let's see if @TruaShamu can find them, or if we have to just give up and assume they're lost.