Update documentation to match function.

Author: IanLee1521

docs/intro.rst

@@ -280,7 +280,7 @@ This is the current list of error and warning codes:
 | E228     | missing whitespace around modulo operator                            |
 +----------+----------------------------------------------------------------------+
 +----------+----------------------------------------------------------------------+
-| E231     | missing whitespace after ','                                         |
+| E231     | missing whitespace after ',', ';', or ':'                            |
 +----------+----------------------------------------------------------------------+
 +----------+----------------------------------------------------------------------+
 | E241 (*) | multiple spaces after ','                                            |