code: function turndown(input) {
          if (!canConvert(input)) {
              throw new TypeError(input + ' is not a string, or an element/document/fragment node.');
          }
          var cardElems = process.call(this, new RootNode(input));
          return createCard(cardElems);
      }
docs: The entry point for converting a string or DOM node to JSON
  @public
  @param {String|HTMLElement} input The string or DOM node to convert
  @returns A Markdown representation of the input
  @type String