title: wkhtmltopdf center the document
body: <p>I am trying to print an html document into a pdf file using wkhtmltopdf.
  How do I pass the parameters to print this html document in the middle of the page?
  currently I run it with :</p>
  
  <pre><code>wkhtmltopdf -O Landscape -s A5 fileName.html fileName.pdf
  </code></pre>