Feed updates

source/blog/tag.xml

@@ -2,19 +2,21 @@
 generator: [posts_tag_index]
 ---
 <?xml version="1.0" encoding="UTF-8" ?>
-<rss version="2.0">
+<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
   <channel>
     <title>{{ site.title }}</title>
     <link>{{ site.url }}</link>
     <language>en</language>
     {% if site.description %}<description>{{ site.description|raw }}</description>{% endif %}
-    {% for post in page.tag_posts|slice(0, 10) %}
+    <atom:link href="{{ site.url }}{{ page.url }}" rel="self" type="application/rss+xml" />
+      {% for post in page.tag_posts|slice(0, 10) %}
       <item>
         <title>{{ post.title }}</title>
         <link>{{ site.url }}{{ post.url }}</link>
         <guid isPermaLink="true">{{ site.url }}{{ post.url }}</guid>
         <pubDate>{{ post.date|date('r') }}</pubDate>
         <description>{{ post.description|raw }}</description>
+        <lastBuildDate>{{ site.calculated_date | date('c') }}</lastBuildDate>
       </item>
     {% endfor %}
   </channel>