[2.7] bpo-33856: Add "help" to the welcome message of IDLE (GH-7755) (GH-7758)

Make it the same as when one runs 'python'..
(cherry picked from commit 9d49f850)
Co-authored-by: Stéphane Wirtel <stephane@wirtel.be>

Lib/idlelib/PyShell.py

@@ -1040,7 +1040,7 @@ class PyShell(OutputWindow):
         return self.shell_title
 
     COPYRIGHT = \
-          'Type "copyright", "credits" or "license()" for more information.'
+          'Type "help", "copyright", "credits" or "license()" for more information.'
 
     def begin(self):
         self.resetoutput()

Misc/NEWS.d/next/IDLE/2018-06-16-21-54-45.bpo-33856.TH8WHU.rst

+Add "help" in the welcome message of IDLE