Add rss feed template

CHWEB-6 #resolve #comment resolved by adding liquid template

Author: Tim Watson

_includes/head.html

@@ -5,7 +5,7 @@
     <meta name="author" content="{{ site.author.name }}"> 
     <!-- Le styles -->
     <link rel="alternate" type="application/rss+xml" href="/rss.xml" title="RSS feed for this page">
-    <link rel="alternate" type="application/atom+xml" href="/atom.xml" title="Atom feed for this page"/>
+    <link rel="alternate" type="application/atom+xml" href="/rss.xml" title="Atom feed for this page"/>
     <link href="/css/bootstrap.css" rel="stylesheet">
     <link href="/css/bootstrap-responsive.css" rel="stylesheet">
     <link href="/css/pygments.css" rel="stylesheet">

rss.xml

@@ -0,0 +1,20 @@
+---
+layout: none
+---
+<?xml version="1.0" encoding="ISO-8859-1" ?>
+<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
+    <channel>
+        <title>{{ site.name }} - Articles</title>
+        <description>{{ site.description }}</description>
+        <link>{{ site.url }}</link>
+        {% for post in site.posts %}
+            <item>
+                <title>{{ post.title }}</title>
+                <description>{{ post.content | xml_escape }}</description>
+                <pubDate>{{ post.date | date: "%a, %d %b %Y %H:%M:%S %z" }}</pubDate>
+                <link>{{ post.link | escape }}</link>
+                <guid isPermaLink="true">{{ site.url }}{{ post.url }}</guid>
+            </item>
+        {% endfor %}
+    </channel>
+</rss>