Add type hints?

[AlexWaygood]

How would we feel about adding type hints to the pyperformance codebase?

Running a type checker on pyperformance might catch some bugs. But more importantly, in my opinion, it would make some parts of the code base a lot easier to read and reason about -- it would be self-evident what kind of object is being accepted and returned by various functions.

There are various tools that we could use to add "obvious" type hints quickly to the code base, such as autotyping and MonkeyType.