Move 'use strict' to file level

Change-Id: I1f0dae4aa168e77c112bcd3688c98b84e4ce5f36
diff --git a/Changes b/Changes
index 73d083d..bfc13aa 100755
--- a/Changes
+++ b/Changes
@@ -1,4 +1,4 @@
-0.40 2020-10-20
+0.40 2020-11-10
         - Modernize ES and fix in-loops.
         - add roll() method to state object.
         - Fix wrong hint-mirror behaviour in Firefox.
@@ -7,6 +7,7 @@
         - Improve JS test coverage for Datepicker.
         - Fix character errors in hint helper at position 0.
         - Improve JS test coverage for tutorial.
+        - Move "use strict" to file level.
 
 0.39 2020-10-07
         - Add information on secret file to Readme.