title: How do create a multi select options? or add attributes to the models.CharField
body: <p>I have this </p>
  
  <pre><code>models.CharField(max_length=10,choices=LOCATION_NAME)
  </code></pre>
  
  <p>However, I want it to render something like this, </p>
  
  <pre><code>&lt;select multiple="multiple"&gt;
   &lt;option value="1"&gt;1&lt;/option&gt;
   &lt;option value="2"&gt;2&lt;/option&gt;
   &lt;option value="3"&gt;3&lt;/option&gt;
   &lt;option value="4"&gt;4&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>I am trying to add this to the django admin section. </p>