feat: simplify layout structure

src/_includes/layouts/post.html

@@ -0,0 +1,19 @@
+---
+layout: "layouts/base"
+---
+
+<article class="[ flow ]">
+    <header class="[ flow ]" style="--flow-space: 1rem">
+        {% from "macros/date.njk" import format %}
+        {{ format(date) }}
+        <h1>{{ title }}</h1>
+        <ul class="[ categories ] [ cluster list-none p-0 ]">
+            {% for tag in tags | filter(["post"]) %}
+                <li class="[ flex gap-0.25 ]">
+                    <a href="/tags/{{ tag | slugify }}">{{ tag }}</a>
+                </li>
+            {% endfor %}
+        </ul>
+    </header>
+    {{ content | safe }}
+</article>