Breaking changes, rewrite; add support for plain text output and single page mode

layouts/_partials/docs/html-head.html

@@ -47,9 +47,8 @@ https://github.com/alex-shpak/hugo-book
 
 {{ partial "google_analytics.html" . }}
 
-<!-- RSS -->
-{{- with .OutputFormats.Get "rss" -}}
-  {{ printf `<link rel="%s" type="%s" href="%s" title="%s" />` .Rel .MediaType.Type .Permalink $.Site.Title | safeHTML }}
+{{- range .AlternativeOutputFormats -}}
+  {{ printf `<link rel="%s" type="%s" href="%s" title="%s" />` .Rel .MediaType.Type .Permalink $.Title | safeHTML }}
 {{ end -}}
 
 {{- define "integrity" -}}