title: Take screenshot of multi-monitor setup
body: <p>I'm taking a screenshot using this line</p>
  
  <pre><code>screen = QPixmap.grabWindow(QApplication.desktop().winId())
  </code></pre>
  
  <p>but apparently that doesn't grab the full desktop if the user has several monitors. </p>
  
  <p>Is there a way to grab the desktop of all monitors into a single image?</p>