title: Using markup with Gtk.TextView
body: <p>I have been trying to find a way to use Pango markup with <code>Gtk.TextView</code> and <code>Gtk.TextBuffer</code> in <em>Python GObject</em>, but it seems like this functionality is only available for tooltips and labels. <code>Gtk.TextBuffer</code> has the <a href="https://lazka.github.io/pgi-docs/#Gtk-3.0/classes/TextBuffer.html#Gtk.TextBuffer.insert_markup" rel="nofollow noreferrer"><code>insert_markup</code></a> method, but requires <code>Gtk.TextIter</code> as input, and must be of specified length.</p>
  
  <p>The issue here is that I want to use <code>Gtk.TextView</code> only for displaying text without it being editable. So while I think I understood how you use <code>Gtk.TextTag</code> with editable/selectable text to change its appearance (and even behaviour) substantially, I am not entirely sure how you do the same with static text. What is the simplest way of applying markup to such?</p>
  
  <p>For example: turning "&lt;b>Some text&lt;/b>" into "<b>Some text</b>" (or whichever tags would be used)</p>