title: How to change font and its size in QLPreviewViewController?
body: <p>In my iOS app, I'm using <code>QLPreviewViewController()</code>. It is presenting a <strong>.txt</strong> file. I want to change the <strong>type</strong> of the font and its <strong>size</strong>. So is it possible to change it or I'm not able to do it?</p>