[amw-zero]

Documentation: "is any communicable material that is used to describe, explain or instruct regarding some attributes of an object, system or procedure, such as its parts, assembly, installation, maintenance and use."

That's a pretty [good definition I think](https://en.wikipedia.org/wiki/Documentation). I also think a type does provide explanation and instructions about how to use typed code. So, I think by definition, types are undeniably documentation.