bpo-37748: Re-order the Run menu. (GH-15115)

Put the most common choice, Run Module, at the top.
diff --git a/Lib/idlelib/mainmenu.py b/Lib/idlelib/mainmenu.py
index fc51fb1..74edce2 100644
--- a/Lib/idlelib/mainmenu.py
+++ b/Lib/idlelib/mainmenu.py
@@ -73,10 +73,10 @@
    ]),
 
  ('run', [
-   ('Python Shell', '<<open-python-shell>>'),
-   ('C_heck Module', '<<check-module>>'),
    ('R_un Module', '<<run-module>>'),
    ('Run... _Customized', '<<run-custom>>'),
+   ('C_heck Module', '<<check-module>>'),
+   ('Python Shell', '<<open-python-shell>>'),
    ]),
 
  ('shell', [