_includes/script.html

<script src="/reveal.js/dist/reveal.js"></script>
<script src="/reveal.js/plugin/markdown/markdown.js"></script>
<script src="/reveal.js/plugin/highlight/highlight.js"></script>
<script src="/reveal.js/plugin/notes/notes.js"></script>
<script src="/reveal.js/plugin/math/math.js"></script>
<script src="/reveal.js/plugin/zoom/zoom.js"></script>
<script>
  Reveal.initialize({
    {% if site.reveal %}
      {% for attr in site.reveal %}{{attr[0]}}: {% unless {attr[1]} == false or {attr[1]} == true %}'{{attr[1]}}',{% else %}{{attr[1]}},{% endunless %}
      {% endfor %}
    {% endif %}
    {% if page.reveal %}
      {% for attr in page.reveal %}{{attr[0]}}: {% unless {attr[1]} == false or {attr[1]} == true %}'{{attr[1]}}',{% else %}{{attr[1]}},{% endunless %}
      {% endfor %}
    {% endif %}
    plugins: [ RevealMarkdown, RevealHighlight, RevealNotes, RevealMath, RevealZoom ],
  });
</script>