DRY up archives by using an include

_pages/collection-archive.html

@@ -16,10 +16,7 @@ permalink: /collection-archive/
   {% endunless %}
   {% for post in collection.docs %}
     {% unless collection.output == false or collection.label == 'posts' %}
-      <article itemscope itemtype="http://schema.org/CreativeWork">
-        <h2 itemprop="headline"><a href="{{ absurl }}{{ post.url }}" title="{{ post.title }}">{{ post.title }}</a></h2>
-        {% if post.excerpt %}<p itemprop="description">{{ post.excerpt | markdownify | strip_html | strip_newlines | escape_once }}</p>{% endif %}
-      </article>
+      {% include post-single.html %}
     {% endunless %}
   {% endfor %}
 {% endfor %}