title: Selecting timeline item 'content' vis.js
body: <p>Is there a way to select a timeline items 'content'? </p>
  
  <pre><code>timeline.on('select', function (properties) {
    alert('selected items: ' + properties.items);
  });
  </code></pre>
  
  <p>This only selects the item id. Can this be done within vis.js or do I need to use something else like jQuery?</p>