Use double ticks for inline code.

Author: daFish

cookbook/form/form_collections.rst

@@ -671,7 +671,7 @@ you need to have a complete custom prototype you can render it yourself:
 .. code-block:: html+jinja
     data-prototype="{% filter escape %}{% include 'AcmeTaskBundle:Task:prototypeTask.html.twig' with { 'form': form.task.get('prototype') } %}{% endfilter %}"
 
-The included `AcmeTaskBundle:Task:prototypeTask.html.twig` contains the
+The included ``AcmeTaskBundle:Task:prototypeTask.html.twig`` contains the
 markup used for the prototype. This way you can not only easily structure
 your prototype-markup, you can also use this markup to render the
 contents of the collection when it already holds items: