Renders document number in admin table

app/views/admin/documents/_list.html.erb

@@ -1,6 +1,7 @@
 <thead>
   <th>Type</th>
   <th>Date</th>
+  <th>Number</th>
   <% unless @event %>
     <th>Event</th>
   <% end %>
@@ -16,6 +17,7 @@
     <tr class="<%= if document.is_public? then "current_listing" end %>">
       <td><%= document.type %></td>
       <td><%= document.date_formatted %></td>
+      <td><%= document.number %></td>
       <% unless @event %>
         <td><%= link_to document.event.name, admin_event_documents_path(document.event) if document.event %></td>
       <% end %>