Write up some documentation

[chrisuehlinger]

Since Paper Programs may have a lot of growth left to do, it might not make sense to write too much documentation. I think for now it would be enough to distill the video tutorial into a text-and-pictures markdown document, and maybe have one or two documents explaining the architecture in more detail than the README.

Given that this would be a small effort that would probably be a big help for new developers, I'm thinking of taking this on first.

[jemgold]

It would be awesome to have some more complex demo programs — it's taking a while to get the hang of what's possible :)

[janpaul123]

It would be pretty straightforward to create a website where you can view all the programs so far created on paperprograms.org, that would be pretty neat.