bpo-37038: Make idlelib.run runnable; add test clause (GH-13560)

diff --git a/Lib/idlelib/NEWS.txt b/Lib/idlelib/NEWS.txt
index 3f19ce7..e1bc009 100644
--- a/Lib/idlelib/NEWS.txt
+++ b/Lib/idlelib/NEWS.txt
@@ -3,6 +3,8 @@
 ======================================
 
 
+bpo-37038: Make idlelib.run runnable; add test clause.
+
 bpo-36958: Print any argument other than None or int passed to
 SystemExit or sys.exit().