switch to managing CSS and JS as assets

themes/hugo-sustain/layouts/partials/head/css.html

@@ -0,0 +1,21 @@
+<!-- Static, third-party CSS -->
+{{- range (slice "css/bootstrap-3.3.7.min.css" "css/fontawesome-all.min.css") }}
+  {{- with resources.Get . }}
+    {{- if eq hugo.Environment "development" }}
+      <link rel="stylesheet" href="{{ .RelPermalink }}">
+    {{- else }}
+      {{- with . | minify | fingerprint }}
+        <link rel="stylesheet" href="{{ .RelPermalink }}" integrity="{{ .Data.Integrity }}" crossorigin="anonymous">
+      {{- end }}
+    {{- end }}
+  {{- end }}
+{{- end }}
+
+<!-- Theme stylesheet, combination of all in assets/scss -->
+{{- $style := resources.Get "scss/main.scss" | resources.ExecuteAsTemplate "scss/main.scss" . | toCSS (dict "targetPath" "css/main.css" "enableSourceMap" false) }}
+<link rel="stylesheet" href="{{ ($style).RelPermalink }}?v={{ md5 time.Now.Unix }}">
+
+<!-- Custom CSS -->
+{{- range .Site.Params.custom_css }}
+<link rel="stylesheet" href="{{ relURL . }}?v={{ md5 time.Now.Unix }}" />
+{{- end }}