title: Include SVG xml in Jade template
body: <p>Is it possible to create a Jade mixin, which reads a file from the file system, and echoes it into the rendered HTML?</p>
  
  <p>I tried this...</p>
  
  <pre><code>mixin svg(file)
      - var fs = require("fs");
      - var xml = fs.readFileSync(file)
      div= xml
  </code></pre>
  
  <p>... but it fails because <code>require</code> does not exist.</p>