Thoughts on TypeScript support? #25

First of all, great project. The simplicity is beautiful.

I am curious on your thoughts on adding typings in some form to this repo from a maintainer perspective. I am happy to do the work here, but don't want to create a maintenance burden.

In order of personal preference:

1. Rewrite/convert the package with TypeScript, using your microbundle package?
2. Add .d.ts files to the current implementation?
3. Create a definitely typed package for @types/vhtml?