feat: created basic blog layout

_includes/post.njk

@@ -0,0 +1,30 @@
+---
+layout: base.njk
+---
+
+<article class="blog-post">
+  <header class="post-header">
+    <h1>{{ title }}</h1>
+    <time datetime="{{ createdAt | dateFormat }}">{{ createdAt | dateFormat }}</time>
+    {% if updatedAt %}
+    <p class="updated-at">Updated: <time datetime="{{ updatedAt | dateFormat }}">{{ updatedAt | dateFormat }}</time></p>
+    {% endif %}
+  </header>
+  
+  <div class="post-content">
+    {{ content | safe }}
+  </div>
+  
+  {% set postTags = page.inputPath | extractTagsFromFile %}
+  
+  {% if postTags.length > 0 %}
+  <section class="post-tags">
+    <h2>Tags</h2>
+    <ul class="tag-list">
+      {% for tag in postTags %}
+        <li><a href="/tags/{{ tag | lower }}/">#{{ tag }}</a></li>
+      {% endfor %}
+    </ul>
+  </section>
+  {% endif %}
+</article>