title: Custom extension in rails routes
body: <p>I have to serve rails generated zip files.
  For example from the following REST route:
  <a href="http://foo.com/controller/show/filename.zip" rel="nofollow noreferrer">http://foo.com/controller/show/filename.zip</a></p>
  
  <p>How i need to map routes.rb to allow the routing of zip files (instead searching for static files in /public) to my controller?</p>