Include typescript declarations in npm package

[rosskevin]

Closes #177

Typescript declarations need to be copied to distributable.

[taion]

@rosskevin I tweaked this a bit... moved index.d.ts to root. Is this okay?

[taion]

This is how I see things set up for Redux, so maybe it's a more common way to do this?

[rosskevin]

That's fine, some are in src when they are split into multiple files, otherwise it can be anywhere.

[taion]

Do we need to tweak tsconfig.json to make this work?

[rosskevin]

I pushed a tsconfig fix after the index.d.ts location change.

[taion]

Great, thanks!

[taion]

v0.3.11