title: How do I create an Autoscrolling TextBox
body: <p>I have a WPF application that contains a multiline TextBox that is being used to display debugging text output. </p>
  
  <p>How can I set the TextBox so that as text is appended to the box, it will automatically scroll to the bottom of the textbox?</p>
  
  <ul>
  <li>I'm using the MVVM pattern.</li>
  <li>Ideally a pure XAML approach would be nice.</li>
  <li>The TextBox itself is not necessarily in focus.</li>
  </ul>