[docs] Add a new site to the showcase

[wzup]

• PR has tests / docs demo, and is linted.
• Commit and PR titles begin with [ComponentName], and are in imperative form: "[Component] Fix leaky abstraction".
• Description explains the issue / use-case resolved, and auto-closes the related issue(s) (http://tr.im/vFqem).

I have added a new site to a list of sites that use material-ui.
No changes to existing components.

[oliviertassinari]

Thanks 😄

[wzup]

And what's next?
I can't see my project here http://www.material-ui.com/#/discover-more/showcase
I also can't see my changes here docs/src/app/components/pages/discover-more/Showcase.js
When will they appear?

[mbrookes]

For the code changes to appear, this commit has to be merged. As I have made another change, I will leave it for another maintainer to review and commit. (Back to you @oliviertassinari!)

Then, it won't appear on the docs site until a new release is published and the docs site updated. (approx. every 2 weeks or so).