feat(typescript): Source code rewrite using typescript (#425)
Rewrote the whole repository into typescript. This will provide way better and up to date documentation. This should also add some safety for people contributing 😄 .
Flow types were not working until now which is why this PR doesn't have them but feel free to PR.
This also fixes #384#435#206#171#168.
Kai Guo
Jamie Birch
Thibault Malbranche
Jamon Holmgren