Add js-doc

https://github.com/mooz/js-doc

Re: mooz/js-doc/issues/1

cc@mooz

I have sent pull requests to `mooz/js-doc` for fixing following issues.

- Add file footer for ELPA compatibility (mooz/js-doc/pull/2)
- Add missing require form (mooz/js-doc/pull/3)
- Add autoload cookies (mooz/js-doc/pull/4)