improve the README structure

Just a small modification to make it easier to read. I also added the dependency section, so it's more clear to see what is need and know how it's done with.

I want to encourage you to continue, I'd' really love to see it output text directly in terminal, although I don't know it's possible. The image output looks very textual. I don't really know anything about this code, but it's really interesting to see it.