Add react-snippets

This is a collection of [Yasnippets] [] for the [React] [] JavaScript library.

[Yasnippets]: https://github.com/capitaomorte/yasnippet
[React]: http://facebook.github.io/react/

The repository is [here] [].

[here]: https://github.com/johnmastro/react-snippets.el

I'm the maintainer. I've built the package locally and tested that it installs and works.