Add css to bower's main property

angular-toggle-switch isn't usable without some styling, which the main
stylesheet provides. A build tool like grunt-bower-install can automatically
inject the file into `index.html` (say).

The bootstrap theme is probably best left off, but perhaps a note should be
added to the readme?

Also switched to non-minified js as per the [bower spec][1].

[1]: https://github.com/bower/bower.json-spec/blob/d8e7299a94b76171135b066ceb570fb4df4caa4c/README.md#main