title: Generating pdf from html using Prawn
body: <p>I want to generate pdf from html. A <code>gem prawn</code> seems to be the most popular one for that. I downloaded the manual for it, but there is no information about how to generate pdf from html.</p>
  
  <p>In particular, I need it to work on Heroku also, but that's the second goal.</p>
  
  <p>So how can I generate pdf from <strong>html</strong> using <code>Prawn</code>?</p>