Revert "Lose brackets?"

This reverts commit 038bbe52da.

_includes/post_detail.html

@@ -1,4 +1,7 @@
 <h1 class="entry-title">
+{% if page.title %}
+    <a href="{{ root_url }}{{ page.url }}">{{ page.title }}</a>
+{% endif %}
 {% if post.title %}
     <a href="{{ root_url }}{{ post.url }}">{{ post.title }}</a>
 {% endif %}