Added Bosonic to the list of libraries

Even if there is still plenty of work to do (better docs, more elements, more features...), I think Bosonic deserves to figure in the list of Web Components libraries, but of course, it's your call ;)

Let me please introduce myself: my name is Raphaël Rougeron (@goldoraf) and I'm a french web developer who falled in love with the Web Components specs. What I wanted to do with Bosonic was to offer a way of authoring custom elements as the spec currently describes, and without introducing a dependency on a library. That's why Bosonic is a sort of a transpiler, that transforms your custom elements definitions into vanilla JS that uses the Polymer polyfills.

In short, my only goal is to help to clear the way for Web Components with an alternative, more vanilla, authoring approach.

Btw, thank you all for your fantastic work on Web Components !

Regards,

Raphaël