Expanding on JoostS answer:
---layout: null---<?xml version="1.0" encoding="UTF-8" ?><rss version="2.0"><channel><title>{{ site.title }}</title><description>{{ site.description }}</description><link>{{ site.url }}</link><lastBuildDate>{{ site.time | date_to_rfc822 }}</lastBuildDate><pubDate>{{ site.time | date_to_rfc822 }}</pubDate><ttl>1800</ttl> {% for post in site.pages %} {% if post.title %}<item><title>{{ post.title }}</title><description>{{ post.description }}</description><link>{{ site.url }}{{ post.url }}</link><guid isPermaLink="true">{{ site.url }}{{ post.url }}</guid><pubDate>{{ post.date | date_to_rfc822 }}</pubDate></item> {% endif %} {% endfor %}</channel></rss>