Add documentation for the non portable components

[gcotelli]

Add missing documentation on the components not covered in the base version of Willow.

[jvanecek]

I've been playing lately on a live documentation for each of the suppliers, as you can see in #101.
The idea is that we have a web app, based on willow of course, with examples on how to create each of the components and how they look with every supplier when they are portable, and with a specific page for each supplier showing the non-portable components they provide.
I aim on an easily extensible model so that every one that loads willow, can define not only its own supplier but use this app to check if the portable components looks as expected and define the proper web view with its non-portable components examples.

Below I show a first version of the docs of the Bootstrap suppliers:

Is a work in progress but any suggestion on style, examples, descriptions, and modeling are welcome