Merge pull request #1150 from alexislefebvre/patch-1

serialization: fix typo on filename

Author: soyuka

core/serialization.md

@@ -553,7 +553,7 @@ services:
 
 ```php
 <?php
-// api/src/Serializer/ApiNormalizer
+// api/src/Serializer/ApiNormalizer.php
 
 namespace App\Serializer;