Allow descriptions for public jobs

Give public jobs a short description that is phrased as a question (<125 characters - 1 character reserved for '?' and 14 characters reserved for "Find out @Boa.").

A list of 5-6 public jobs recently made public by Boa users can be featured on the Boa home page. And possibly auto-tweeted (a twitter feed can also be embedded on the web-page).