Move to custom SSG instead of eleventy.

docs/renderer/nodes/Markdown.njk

@@ -0,0 +1,11 @@
+{% macro render(node) %}
+  <div class="
+    prose text-base
+    prose-p:mb-2 prose-ul:my-1 prose-ul:pl-0 prose-ul:ml-6
+    md:prose-p:mb-4 md:prose-ul:pl-4 md:prose-ul:ml-2 md:prose-ul:my-2
+    prose-li:my-0 text-current
+    {{node.class}}
+  ">
+    {{ node.text | safe }}
+  </div>
+{% endmacro %}