Merge branch '5.1' into 5.2

* 5.1:
  [#14561] Fixed wrong reference

Author: wouterj

serializer/custom_encoders.rst

@@ -66,7 +66,7 @@ that's done automatically!
 
 .. tip::
 
-    If you're not using :ref:`autoconfigure <service_autoconfigure>`, make sure
+    If you're not using :ref:`autoconfigure <services-autoconfigure>`, make sure
     to register your class as a service and tag it with ``serializer.encoder``.
 
 Now you'll be able to serialize and deserialize YAML!