update header

templates/blog/post/posts.html.twig

@@ -8,6 +8,14 @@
     {{- _page.title.value -}}
 {% endblock %}
 
+{%- block page_subtitle -%}
+    {% if _page.subTitle.value %}
+        <p class="h3">
+            {{- _page.subTitle.value -}}
+        </p>
+    {% endif %}
+{% endblock %}
+
 {% block body %}
     {% for post in pager %}
         {% if not loop.first %}