title: javascript in twig file do not execute
body: <p>when I try to put some script in a twig file , and finally they do not execute, for example:  </p>
  
  <pre><code>{% block myJavascript %}
  &lt;script type="text/javascript"&gt;
  &lt;!--
  alert("test");
  {% endblock %}  
  </code></pre>
  
  <p>in my index.html.twig<br>
  I see it in the generate html code but it just do not execute. Anyone has some idea?</p>