code: function rewriteFonts () {
    const style = path.join(target, 'css', 'style.css')
    const css = fs.readFileSync(style)
      .toString()
      .replace(/@import url\(.*?Roboto.*?\);/, `@import url('https://fonts.googleapis.com/css?family=Open+Sans:400,600|Source+Code+Pro:400,600');`)
      .replace(/Roboto/g, 'Open Sans')
  
    fs.writeFileSync(style, `
      ${css}
  
      code {
        font-family: 'Source Code Pro', monospace;
      }
  
      pre > code {
        padding: 0.75em 1em;
        line-height: 1.5em;
      }
  
      ul, ol {
        margin-bottom: 15px;
      }
  
      hr {
        border: 0;
        height: 2px;
        background: #f5f5f5;
        margin: 15px 0;
      }
  
      blockquote {
        border-left: 3px solid #eee;
        padding-left: 0.75em;
        margin-bottom: 15px;
        color: #999;
        font-size: 0.9em;
      }
    `)
  }
docs: Rewrites the fonts in the output CSS to replace them with our own.
  Do this instead of overriding for load times and reduction in hackery.