Add RSS link to header (#1019)

Co-authored-by: Emruz Hossain <hossainemruz@gmail.com>

layouts/partials/header.html

@@ -18,3 +18,7 @@
 
   <link rel="icon" type="image/png" href="{{ $favicon }}" />
 {{end}}
+
+{{ with .OutputFormats.Get "rss" -}}
+  {{ printf `<link rel=%q type=%q href=%q title=%q>` .Rel .MediaType.Type .Permalink site.Title | safeHTML }}
+{{ end }}