add rss feed to head.html

layouts/partials/head.html

@@ -1,5 +1,9 @@
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width">
 <title>{{ if .IsHome }}{{ site.Title }}{{ else }}{{ printf "%s | %s" .Title site.Title }}{{ end }}</title>
-{{ partialCached "head/css.html" . }}
-<link rel="shortcut icon" href="{{ site.Params.favicon }}">
+{{- partialCached "head/css.html" . }}
+<link rel="shortcut icon" href="{{ site.Params.meta.favicon }}">
+
+{{ with .OutputFormats.Get "rss" }}
+  {{- printf `<link rel=%q type=%q href=%q title=%q>` .Rel .MediaType.Type .Permalink site.Title | safeHTML }}
+{{- end }}