pythongh-84910: Change 'IDLE Help' to 'IDLE Doc' (python#95873)

'IDLE Help' was a plain text file.  It was superceded years ago
by a copy of the much more complete html doc.  .

Author: terryjreedy

Lib/idlelib/mainmenu.py

@@ -111,7 +111,7 @@
  ('help', [
    ('_About IDLE', '<<about-idle>>'),
    None,
-   ('_IDLE Help', '<<help>>'),
+   ('_IDLE Doc', '<<help>>'),
    ('Python _Docs', '<<python-docs>>'),
    ]),
 ]