Add settings for contact information

app/views/admin/settings/index.html.haml

@@ -20,3 +20,9 @@
         and
         %code= '<em>'
       %td= best_in_place @settings['site_description'], :value, as: :textarea, url: admin_setting_path(@settings['site_description'])
+    %tr
+      %td{ rowspan: 2 }
+        %strong Contact information
+      %td= best_in_place @settings['site_contact_username'], :value, url: admin_setting_path(@settings['site_contact_username']), place_holder: 'Enter a username'
+    %tr
+      %td= best_in_place @settings['site_contact_email'], :value, url: admin_setting_path(@settings['site_contact_email']), place_holder: 'Enter a public e-mail address'