Keep scss separate (#478)

Author: jarrodmillman

assets/theme-css/scientific-python-hugo-theme.scss

@@ -0,0 +1 @@
+@import "./code";

assets/theme-css/spht/index.scss

@@ -22,7 +22,11 @@
 <link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Noto+Sans+Symbols+2">
 
 <!-- Process and include Sass files. -->
-{{- $sass := (resources.Match "theme-css/*.scss") | append (resources.Match "css/*.scss") -}}
+{{- $sass := append (resources.Get "theme-css/sphinx-design/index.scss")
+                    (resources.Get "theme-css/pst/pydata-sphinx-theme.scss")
+                    (resources.Get "theme-css/spht/index.scss")
+                    (resources.Match "theme-css/*.scss")
+           | append (resources.Match "css/*.scss") -}}
 
 {{- range $sass -}}
   {{ with . }}  <!-- Skips nil elements from appending empty resources.Match slices. -->