title: Swift UITextView with different formatting
body: <p>Sorry for a basic question, but I'm not sure where to start. Is the following possible in Swift?</p>
  <blockquote>
  <p>In a <em>UITextView</em> (Not a label, as in the possible duplicate), different bits of text having different formatting: for instance, a line of large text in the same UITextView as a line of small text. Here is a mockup of what I mean:
  <img src="https://i.stack.imgur.com/Pbk6Z.png" alt="enter image description here" /></p>
  </blockquote>
  <p>Is this possible in one UITextView?</p>