Add documentation and models for users

[the-maldridge]

This is my first take at adding users. I think it will allow us to get pretty far in, then after this works well we can add the logic around events and seasons.

[gdyoung93]

Are you going to use firstname and lastname for users? Some users have multiple parts to a name. Here are some real examples Mary Elpseth Anderson Tien Shang Wang Mohammad El Basri

If you use only a "name" field in the data model, it because very difficult to split first name from last name if that is ever needed, and it will be.

[the-maldridge]

Good catch, I'll split this field into two different fields, unless you think there's another way we should be storing the name.