add a title for the tagged posts page..

layout/tagged_posts.j2

@@ -1,6 +1,10 @@
 {% from "macros.j2" import itemurl %}
 {% extends "base.j2" %}
 
+{% block title %}
+{{ tag.name }}
+{% endblock %}
+
 {% block main %}
 <section class="archives">
 <h1 class="tag title">{{ tag.name }}</h1>