scaffold unprompted site: eleventy, templates, gitea CI

_includes/sidebar.njk

@@ -0,0 +1,21 @@
+<aside class="sidebar">
+  <nav class="sidebar-nav">
+    <h2>archive</h2>
+    {%- set currentYear = null -%}
+    {%- for column in collections.columns %}
+      {%- set colYear = column.date | year -%}
+      {%- if colYear != currentYear %}
+        {%- if currentYear != null %}
+        </ul>
+        {%- endif %}
+        {%- set currentYear = colYear %}
+        <h3 class="year-label">{{ colYear }}</h3>
+        <ul>
+      {%- endif %}
+          <li><a href="{{ column.url }}">{{ column.data.title }}</a></li>
+    {%- endfor %}
+    {%- if currentYear != null %}
+    </ul>
+    {%- endif %}
+  </nav>
+</aside>