[3.12] gh-86206: Change IDLE splash line (GH-129698) (#129718)

Replace references to boilerplate files available in About IDLE and instead suggest clicking Help menu.

(cherry picked from commit d83a8a2)

Co-authored-by: Stan Ulbrych <[email protected]>
Co-authored-by: Terry Jan Reedy <[email protected]>

Author: 3 people

Lib/idlelib/pyshell.py

@@ -1131,8 +1131,7 @@ def ispythonsource(self, filename):
     def short_title(self):
         return self.shell_title
 
-    COPYRIGHT = \
-          'Type "help", "copyright", "credits" or "license()" for more information.'
+    SPLASHLINE = 'Enter "help" below or click "Help" above for more information.'
 
     def begin(self):
         self.text.mark_set("iomark", "insert")
@@ -1151,7 +1150,7 @@ def begin(self):
             sys.displayhook = rpc.displayhook
 
         self.write("Python %s on %s\n%s\n%s" %
-                   (sys.version, sys.platform, self.COPYRIGHT, nosub))
+                   (sys.version, sys.platform, self.SPLASHLINE, nosub))
         self.text.focus_force()
         self.showprompt()
         # User code should use separate default Tk root window