feat(website): add content structure files

packages/website/templates/partials/header.html

@@ -0,0 +1,18 @@
+<ul>
+  <li>
+    <a href="/">Overview</a>
+  </li>
+
+  {% for item in get_taxonomy(kind="section") | get(key="items") %}
+    <li>
+      <a href="{{ get_url(path="@/" ~ item.slug ~ "/_index.md") }}">{{ item.name | title }}</a>
+      <ul class="msp-d-none">
+        {% for page in item.pages %}
+          <li>
+            <a href="{{ page.permalink }}">{{ page.title | default(value=page.slug) | title }}</a>
+          </li>
+        {% endfor %}
+      </ul>
+    </li>
+  {% endfor %}
+</ul>