Add basic types

This one may be a bit verbose for a single post, but take a look and let me know what you think. If anything, we could break this out into a couple posts, like Numbers, Collections, Binaries, Strings and Charlists. I guess I want to test the waters here and see what your thoughts are on post length, etc.

Though this post is longer, I make a point to not go out of my way explaining every little thing about the types. It's basically a high-level overview of each type, with some simple examples of using each in IEx.