Merge pyi files into py files

[CraftSpider]

Closes #10

Removes all .pyi files, merging them into .py. Reduces need for upkeep of two files at once, and makes the docs include types for arguments.

[CraftSpider]

This is something of a step for #25, as having all the types in the documentation is a good start.

[JayDwee]

Needs changes added to History.md btw (I'll let Sergeileduc do the rest of the review)

[Sergeileduc]

I merge this ASAP.