docs(ngInit): update example to use a module

src/ng/directive/ngInit.js

@@ -29,14 +29,15 @@
  * @param {expression} ngInit {@link guide/expression Expression} to eval.
  *
  * @example
-   <example>
+   <example module="initExample">
      <file name="index.html">
    <script>
-     function Ctrl($scope) {
-       $scope.list = [['a', 'b'], ['c', 'd']];
-     }
+     angular.module('initExample', [])
+       .controller('ExampleController', ['$scope', function($scope) {
+         $scope.list = [['a', 'b'], ['c', 'd']];
+       }]);
    </script>
-   <div ng-controller="Ctrl">
+   <div ng-controller="ExampleController">
      <div ng-repeat="innerList in list" ng-init="outerIndex = $index">
        <div ng-repeat="value in innerList" ng-init="innerIndex = $index">
           <span class="example-init">list[ {{outerIndex}} ][ {{innerIndex}} ] = {{value}};</span>