Add a page for all the rad uses of Pixyll in the wild

This can also serve as a place to aggregate all the forks/deployments to share, I'll start with @mgrachev's epic site
- http://www.mgrachev.com/

Start by inspecting Pixyll's existing Jekyll pages and navigation to find the appropriate location for a showcase page. Use the issue's example, http://www.mgrachev.com/, as the first entry; done means the page aggregates Pixyll forks or deployments in a shareable format and is linked from the site.

Written by the indexing model from the issue text.