Pass an additional parameter to base/head/css.html

Pass the path of a stylesheet resource to this template so it can be used to
generate other CSS stylesheets.

layouts/partials/base/head.html

@@ -1,5 +1,5 @@
 <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 "base/head/css.html" . }}
+{{ partialCached "base/head/css.html" (dict "page" . "cssResource" "base/css.html") }}
 {{ partialCached "base/head/js.html" . }}

layouts/partials/base/head/css.html

@@ -1,4 +1,4 @@
-{{- with (partial "base/css.html" .) }}
+{{- with (partial .cssResource .page) }}
   {{- if eq hugo.Environment "development" }}
     <link rel="stylesheet" href="{{ .RelPermalink }}">
   {{- else }}