adds to settings doc

node/src/documents/modules/form.html

@@ -310,6 +310,11 @@ type   : 'UI Behavior'
         <td>value, notValue</td>
         <td>Checks whether a field is not a value</td>
       </tr>
+      <tr>
+        <td>contains</td>
+        <td>value, text</td>
+        <td>Checks whether a field contains text</td>
+      </tr>
       <tr>
         <td>is</td>
         <td>value, text</td>