code: function getCssFontsUrl(options) {
    if (options.cssFontsUrl) {
      return options.cssFontsUrl
    } if (options.cssPath) {
      return path.relative(path.dirname(options.cssPath), options.outputDir)
    }
  
    return './'
  }
docs: Based on given options, compute value that should be used as a base URL for font files from the generated CSS
  
  If a `cssFontsUrl` option is explicitally provided, it overrides default behaviour
  
  Else if the CSS was output at a custom filepath, compute a relative path from there
  
  Just return './' otherwise
  
  @param  {Object} options
  @return {void}