docs: function parsePlaceholders (source) {
    return source.match(/\([^\)]+\)/g).reduce(function (result, placeholder) {
      placeholder = placeholder.replace(/^\(([^\)]+)\)$/, '$1');
      var keyValue = placeholder.split(':');
      result[keyValue[0]] = {
        content: keyValue[1]
      };
      return result;
    }, {});
  }