docs(misc core): fixed broken angular.copy example

The module was not being registered, and this broke the example for who knows how long!

Closes #8218

src/Angular.js

@@ -735,7 +735,7 @@ function isLeafNode (node) {
  </div>
 
  <script>
-  angular.module('copyExample')
+  angular.module('copyExample', [])
     .controller('ExampleController', ['$scope', function($scope) {
       $scope.master= {};