Add a concept of "person"

[nbudin]

This idea suggested by @japilo. Thanks July!

Larp Library doesn't actually understand the concept of individual people right now (when it comes to authorship of larps etc.). It would be cool to add one, and that way people could search Larp Library for everything a given person worked on regardless of what brand it was published under.

I'm thinking we should probably model this as three tables:

• people
• person_names
• project_people

people is obvious; person_names is for representing the concept of people having multiple names they go by. person_names should probably be able to specify which name is the person's "default" name if it's otherwise unspecified in our data. project_people is a has_many :through-style join table, which allows us to override which person_name is used on a particular project.

I have no idea what the UI looks like for this yet 😅