docs: function absoluteCss (css, resolveTo) {
    const urlRegex = /url\(\s?["']?([^)'"]+)["']?\s?\).*/i
  
    let index = 0
    let found
    while ((found = urlRegex.exec(css.substring(index))) !== null) {
      const rawSrc = found[1]
      const encodedSrc = encodeUrl(rawSrc.trim())
      if (isProtoless(encodedSrc)) {
        const resolvedSrc = url.resolve(resolveTo, encodedSrc)
        const foundIndex = found.input.indexOf(rawSrc)
  
        css =
          css.slice(0, index + foundIndex) +
          resolvedSrc +
          css.slice(index + foundIndex + rawSrc.length)
  
        index += resolvedSrc.length - rawSrc.length
      }
      index += found.index + rawSrc.length
    }
  
    return css
  }