title: RailsAdmin DSL - Show all fields, with only one read_only
body: <p>In order to make a model attribute read only in the rails_admin panel you must do something like this:</p>
  
  <pre><code>  config.model Style do
      field :review_count do
        read_only true
      end
    end
  </code></pre>
  
  <p>The problem with doing this is now Style shows no other fields. I don't want to manually go through each model adding in the fields with this DSL. Is there a way to include all fields as editable by default while making one or two read only?</p>
  
  <p><a href="https://github.com/sferik/rails_admin/wiki/Railsadmin-DSL" rel="nofollow">https://github.com/sferik/rails_admin/wiki/Railsadmin-DSL</a></p>