title: html2pdf page numbering
body: <p>I have code like this:</p>
  
  <pre><code>$html2pdf = new HTML2PDF('P','A4','en');
  $html2pdf-&gt;WriteHTML($html);
  $html2pdf-&gt;Output();
  </code></pre>
  
  <p>How add page number at the bottom of the document?</p>