Example — Shadertoy background

A full-screen verso.shadertoy plasma background (data/shaders/examples/
example_bg.330.frag) with text layered on top.

Run:  ./VersoDemo --input data/example-shadertoy.json

CODE:  VersoDemo examples
MUSIC: test.mp3 (placeholder)

If you're using Windows and missing DLLs then install the x64 version of
Microsoft Visual C++ Redistributable for Visual Studio 2019.
