Create beginner's guide to FD/CA

[unicornsasfuel]

It was suggested to me that we should have a tutorial for using FD/CA where we walk through the first few sets of cryptopals with it. This is a nice idea! Even if we don't use cryptopals, tutorials on how to use FD/CA would be great.

[unicornsasfuel]

I've started with a basic usage guide, but I think this tutorial is a pretty large and messy thing to include with FD/CA itself, so it will likely go into a separate repo.