title: Remove and then add same element to Packery JS
body: <p>I want to remove 2 elements and then add them back to a grid built with Packery when a button is clicked. The code is given below:</p>
  
  <pre><code>$('.append-button').on( 'click', function() {
    // create new item elements
    var $items = getItemElement().add( getItemElement() ).add( getItemElement() );
    var $items2 =  $('.big');
    var el = $items2;
  
    // remove and then append elements to container
    $grid.packery('remove', $items2).packery('layout')
    $grid.append( $items2 )
      // add and lay out newly appended elements
      .packery( 'appended', $items2 );
  });
  </code></pre>
  
  <p>If I do this, the elements referenced by <code>$items2</code> appear on reload of Packery but then disappears. <a href="http://codepen.io/anon/pen/LWKerq" rel="nofollow noreferrer">Codepen demo here</a>. Does anyone know how I can delete the 2 elements and then add them back in a stable manner? Thanks in advance!!</p>