bpo-33821: Update IDLE section of What's New 3.7 (python#15036)

* bpo-33821: Update IDLE section of What's New 3.7

* Fix roles.

Author: terryjreedy

Doc/whatsnew/3.7.rst

@@ -1017,11 +1017,20 @@ by right-clicking the button.  (Contributed by Tal Einat in :issue:`1529353`.)
 
 The changes above have been backported to 3.6 maintenance releases.
 
+NEW in 3.7.4:
+
+Add "Run Customized" to the Run menu to run a module with customized
+settings. Any command line arguments entered are added to sys.argv.
+They re-appear in the box for the next customized run.  One can also
+suppress the normal Shell main module restart.  (Contributed by Cheryl
+Sabella, Terry Jan Reedy, and others in :issue:`5680` and :issue:`37627`.)
+
 New in 3.7.5:
 
 Add optional line numbers for IDLE editor windows. Windows
 open without line numbers unless set otherwise in the General
-tab of the configuration dialog.
+tab of the configuration dialog.  Line numbers for an existing
+window are shown and hidden in the Options menu.
 (Contributed by Tal Einat and Saimadhav Heblikar in :issue:`17535`.)