Serve basic pages from content-store

Get an item from the content store and display it on a page. Views are very basic at this point, and controller just passes the content hash directly to the page.

This looks like a hangover from whitehall. Why not simply `get '*path" => 'documents#show'`? Then you can use `params[:path]` in the controller rather than access the request, which is a bit more idiomatic.