add video conversion script

[infoburp]

ffmpeg -i input.mp4 frame%04d.png

for f in *.png; do
./Evolve "$f"
done

ffmpeg -i %05d.render.png output.mp4

[tux3]

I'm not sure it's really in the scope of the repo.

[infoburp]

I created a userscripts repo for mad stuff like this
https://github.com/infoburp/Evolve-userscripts/