Exclude hidden posts from feed.

feed.xml

@@ -9,6 +9,7 @@ redirect_from: "/rss"
 		<link>{{ site.url }}</link>
 		<atom:link href="{{ site.url }}/feed.xml" rel="self" type="application/rss+xml" />
 		{% for post in site.posts limit:10 %}
+            {% if post.hidden == null or post.hidden == false %}
                 <item>
                     <title>{{ post.title | xml_escape }}</title>
                     <description>{{ post.content | xml_escape }}</description>
@@ -16,6 +17,7 @@ redirect_from: "/rss"
                     <link>{{ site.url }}{{ post.url }}</link>
                     <guid isPermaLink="true">{{ site.url }}{{ post.url }}</guid>
                 </item>
+            {% endif %}
 		{% endfor %}
 	</channel>
 </rss>