fixed broken markdown

fixes #6084

docs/guide/structure-applications.md

@@ -140,7 +140,7 @@ For example,
 > Info: If a module ID is the same as an application component ID, the application component will be used during
   the bootstrapping process. If you want to use the module instead, you may specify it using an anonymous function
   like the following:
->```php
+> ```php
 [
     function () {
         return Yii::$app->getModule('user');