Typescript Migration

[ghost1face]

Took a first stab at migrating this library to Typescript and validating implementation in a current project to ensure no errors. This builds on #61 and instead of updating definitions, goes for a like for like, typescript rewrite.

There is one area where I wasn't sure what the use case was. This is in the DefaultRenderer where I put a TODO

I figure if this is a go we can take the following steps in subsequent releases:

1. Migrate to Typescript
2. Use functional components and maybe expose helpful hooks
3. Upgrade rxjs dependency (or possibly remove it to make this 0 dependencies if possible)