Accept None as start and stop parameters for list.index() and tuple.index()

Closes #13340.
diff --git a/Misc/NEWS b/Misc/NEWS
index d053a2b..2f7b54e 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -9,6 +9,9 @@
 Core and Builtins
 -----------------
 
+- Issue #13340: Accept None as start and stop parameters for
+  list.index() and tuple.index().
+
 - Issue #10519: Avoid unnecessary recursive function calls in
   setobject.c.