Typescript types

[notourist]

I added and polished the types from @ChadJPetersen (https://gist.github.com/ChadJPetersen/2e2587bbd753c6a384c02519183e2031). If you don't want to merge #112, 5bc7e31 needs to be reverted.

This also fixes #80

[jsdtaylor]

@usr14 can you use params?: unknown instead of any?

[jbrownson]

I'm looking at using react-graph-vis in a Typescript project and it would be great to have types, is this just being held up by the change requested by @jsdtaylor?