title: Add page title below image in datatables
body: <p>I have added an image to the pdf document as per the documentation at <a href="https://datatables.net/extensions/buttons/examples/html5/pdfImage.html" rel="nofollow noreferrer">https://datatables.net/extensions/buttons/examples/html5/pdfImage.html</a>
  This displays the image below the page title. However, I want the image on top of the title. How can I change the ordering of these two elements? </p>
  
  <p>Below is the javascript code I am using:</p>
  
  <pre><code>$('#dataTable').DataTable( {
      dom: 'Bfrtip',
      "pageLength": 50,
      buttons: [
          'copy', 'excel',
          {
              extend: 'pdfHtml5',
              customize: function ( doc ) {
                  doc.content.splice( 1, 0, {
                      image: 'data:image/png;base64,==image-text-here==',
                      margin: [ 0, 0, 0, 12 ],
                      alignment: 'center',
                      width: 250,
                      height: 100
                  } );
              }
          }, 'print'
      ]
  } );
  </code></pre>