Close #16036: Backport 3.x documentation improvement.

See changeset 6ccb04c4cbae for the corresponding 3.3 change.
diff --git a/Misc/NEWS b/Misc/NEWS
index 759ec4d..94ee943 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -459,6 +459,9 @@
 Documentation
 -------------
 
+- Issue #16036: Improve documentation of built-in int()'s signature and
+  arguments.
+
 - Issue #15935: Clarification of argparse docs, re: add_argument() type and
   default arguments.  Patch contributed by Chris Jerdonek.