TypeScript support out of box

Hi, thank you for writing this plugin. Apologies if this issue has been opened already.

Does this have TS support out of the box?

TS definitions could go a long way for folks adding this to existing TS projects! I believe this would need a `.d.ts` file that could be included.

[Publishing Types](https://www.typescriptlang.org/docs/handbook/declaration-files/publishing.html)