fixing single_text references in date_widget

Author: jseverson

reference/forms/types/options/date_widget.rst.inc

@@ -1,9 +1,9 @@
 * ``widget`` [type: string, default: ``choice``]
-    Type of widget used for this form type.  Can be ``text`` or ``choice``.  
-    
-      * ``text``: renders a three field input of type text (month, day, year). 
+    Type of widget used for this form type.  Can be ``text`` or ``single_text`` or ``choice``.
 
-      * ``single-text``: renders a single input of type text. User's input is validated
+      * ``text``: renders a three field input of type text (month, day, year).
+
+      * ``single_text``: renders a single input of type text. User's input is validated
         based on the ``format`` option.