title: phalcon volt "javascript_include" how to add async or defer in the include URL
body: <p>when i use this line of code in .volt</p>
  
  <pre><code>{{ javascript_include('https://maps.googleapis.com/maps/api/js?key=AIzaSyBizbimR5WObPb2Euy4ICC-dZp8Mm7Y7cM&amp;callback=initMap') }}
  </code></pre>
  
  <p>in view source of the browser it shows like this </p>
  
  <pre><code>&lt;script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyBizbimR5WObPb2Euy4ICC-dZp8Mm7Y7cM&amp;callback=initMap"&gt;&lt;/script&gt;
  </code></pre>
  
  <p>and my map doesn't work it requires "defer" in include url like below output</p>
  
  <p>how i can achieve below using  <code>javascript_include</code></p>
  
  <pre><code>&lt;script async defer
      src="https://maps.googleapis.com/maps/api/js?key=AIzaSyBizbimR5WObPb2Euy4ICC-dZp8Mm7Y7cM&amp;callback=initMap"&gt;
      &lt;/script&gt;
  </code></pre>