Add new features

I finally finished this :), to see how it works I've added info in the README.

**Important**

1. I created a `snippets` folder for every snippet file. If you don't think it's appropriate let me know and I'll revert this change.
2. In case you didn't see it, you can [add messages to your users](https://github.com/caiogondim/jasmine-sublime-snippets/issues/9#issuecomment-46585468) :).

That's all!