Adding link to RSS feed to the <head>

This is a common practice to have such a link. It helps feed aggregators to recognize RSS feeds automatically. At the moment feedly.com (the aggregator I use) can not recognize http://clojure.by/ url, probably there are others. With this addition it will work fine.
Merge pull request #13 from DNNX/patch-2

Adding link to RSS feed to the <head>