on() { return !!document.querySelector( '[data-markdown]' ); } },
                    { src: 'reveal-js/plugin/markdown/markdown.js',
                      condition: function() { return !!document.querySelector( '[data-markdown]' ); } },
                    { src: 'reveal-js/plugin/highlight/highlight.js',
                      async: true, callback: function() { hljs.initHighlightingOnLoad(); } },
                    { src: 'reveal-js/plugin/zoom-js/zoom.js', async: true },
                    { src: 'rev