[Translation] Translatable parameters

Author: alamirault

translation.rst

@@ -345,6 +345,10 @@ Templates are now much simpler because you can pass translatable objects to the
     <h1>{{ message|trans }}</h1>
     <p>{{ status|trans }}</p>
 
+.. tip::
+
+    The translation parameters can also be a :class:`Symfony\\Component\\Translation\\TranslatableMessage`.
+
 .. tip::
 
     There's also a :ref:`function called t() <reference-twig-function-t>`,