UserManual/index.rst: Doc updated for radio/maxlength.

extension/Documentation/UsersManual/Index.rst

@@ -739,6 +739,7 @@ Type: radio
   * c) Definition of the *enum* or *set* field (only labels, no ids are possible).
 
 * FormElement '''Maxlength''' - Vertical or Horizontal alignment:
+
    * '', 0, 1: Vertical.
    * >1: every n'th elements a `<br>`.