Add more intro/tutorial content

[gdcutting]

Per discussion at today's meeting, it's a good idea to add some more content showing OCCAM workflow in a tutorial format. There is a tiny bit of this at the what-is pages, but more would be helpful. Someone who wants to understand how OCCAM can help them and how to use it if they decide to would make it more likely for people to try it out. It would not be very clear how to start using OCCAM if someone just installed it from the repo, so helping people get started with it is a good goal. Doesn't have to be a lot of content (just a few pages).