GH-99749: Add What's New entry for GH-124456 (GH-125671)

Author: savannahostrowski

Doc/whatsnew/3.14.rst

@@ -210,6 +210,11 @@ argparse
   interpreter was instructed to find the ``__main__`` module code.
   (Contributed by Serhiy Storchaka and Alyssa Coghlan in :gh:`66436`.)
 
+* Introduced the optional *suggest_on_error* parameter to
+  :class:`argparse.ArgumentParser`, enabling suggestions for argument choices
+  and subparser names if mistyped by the user.
+  (Contributed by Savannah Ostrowski in :gh:`124456`)
+
 ast
 ---