Use alternate rel for canonical

layouts/_default/list.atom.xml

@@ -68,7 +68,13 @@
     <id>{{ $id }}</id>
 
     {{ range $page.OutputFormats }}
-        {{ $rel := cond (eq .Permalink $page.Permalink) "self" .Rel }}
+        {{ $rel := .Rel }}
+
+        {{ if eq .Permalink $page.Permalink }}
+            {{ $rel = "self" }}
+        {{ else if eq $rel "canonical" }}
+            {{ $rel = "alternate" }}
+        {{ end }}
 
         {{ if or (eq $rel "alternate") (eq $rel "enclosure") (eq $rel "related") (eq $rel "self") (eq $rel "via") }}
             {{ printf `<link href="%s" rel="%s" type="%s"/>` .Permalink $rel .MediaType | safeHTML }}