clarify except* documentation

Author: yangdanny97

Doc/reference/compound_stmts.rst

@@ -378,8 +378,8 @@ exception group with an empty message string. ::
    ...
    ExceptionGroup('', (BlockingIOError()))
 
-An :keyword:`!except*` clause must have a matching type,
-and this type cannot be a subclass of :exc:`BaseExceptionGroup`.
+An :keyword:`!except*` clause must have a matching type or a tuple of matching
+types, which cannot be a subclass of :exc:`BaseExceptionGroup`.
 It is not possible to mix :keyword:`except` and :keyword:`!except*`
 in the same :keyword:`try`.
 :keyword:`break`, :keyword:`continue` and :keyword:`return`