minor symfony#11237 use correct code-block type (OskarStark)

This PR was merged into the 3.4 branch.

Discussion
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use correct code-block type

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Commits
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b4117c5 use correct code-block type

Author: OskarStark

doctrine/registration_form.rst

@@ -366,7 +366,6 @@ Next, create the template:
 .. code-block:: html+twig
 
     {# app/Resources/views/registration/register.html.twig #}
-
     {{ form_start(form) }}
         {{ form_row(form.username) }}
         {{ form_row(form.email) }}

page_creation.rst

@@ -141,7 +141,7 @@ Finally, template files should live in the ``app/Resources/views`` directory. Cr
 a new ``app/Resources/views/lucky`` directory with a new ``number.html.twig`` file
 inside:
 
-.. code-block:: twig
+.. code-block:: html+twig
 
     {# app/Resources/views/lucky/number.html.twig #}