Add images to README

[1j01]

A screenshot of the GUI, and some example programs, of which I have now a lot:

(Sorting by size to get a pseudo-random smattering, due to PNG compression, further down there are less complex images (in terms of data or entropy or whatever), especially with single-color backgrounds:)

I also did some fun tree ones, like this guy, a sort of botanical zebra,
which you can download, import, reanimate and reseed: