Move to custom SSG instead of eleventy.

docs/renderer/nodes/TableOfContents.njk

@@ -0,0 +1,19 @@
+{% macro renderHeadings(headings) %}
+  <ul class="pl-4">
+    {% for heading in headings %}
+      <li class="my-4">
+        <a href="#{{ heading.slug }}" class="hover:text-primary-400">{{ heading.text }}</a>
+        {% if heading.children %}
+          {{ renderHeadings(heading.children)}}
+        {% endif %}
+      </li>
+    {% endfor %}
+  </ul>
+{% endmacro %}
+
+{% macro render(node, ctx) %}
+  <div class="my-4 font-medium text-2xl">Table of Contents</div>
+  <div class="-ml-3">
+    {{ renderHeadings(ctx.headings) }}
+  </div>
+{% endmacro %}