Generation of palette-based PNGs. I wanted to write this entirely by hand, but it turns out that the PNG compression algorithm is more complicated than I want to deal with right now (I might end up switching to GIF later as that algo is simpler). So, I pulled in zlib and banged my head against it until it worked. Having test data from http://www.schaik.com/pngsuite/pngsuite_bas_png.html to do byte-by-byte comparisons via xxd helped a lot
Feeling very excited about how this is going to look on the wiki. https://clarity.flowers/wiki/notate.html
playing with sizing. this is the narrowest possible staff height (a charmingly awkward 9 pixels)