chore(scripts): generic way to build scripts (#829)

* chore: move core scripts

* chore: extract head scripts

layouts/_partials/head.html

@@ -55,32 +55,17 @@
 
   {{ partial "components/analytics/analytics.html" . }}
 
-  <script>
-    // The section must not be in the theme.js file because it can create a quick flash (switch between light and dark).
+  {{- $scriptsHead := slice -}}
+  {{- range resources.Match "js/head/*.js" -}}
+    {{ $scriptsHead = $scriptsHead | append (resources.ExecuteAsTemplate .Name $ .) }}
+  {{- end -}}
 
-    function setTheme(theme) {
-      document.documentElement.classList.remove("light", "dark");
+  {{- $scripts := $scriptsHead | resources.Concat "js/main-head.js" -}}
 
-      if (theme !== "light" && theme !== "dark") {
-       theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "dark" : "light";
-      }
-
-      document.documentElement.classList.add(theme);
-      document.documentElement.style.colorScheme = theme;
-    }
-
-    setTheme("color-theme" in localStorage ? localStorage.getItem("color-theme") : '{{ site.Params.theme.default | default `system`}}')
-
-  </script>
-
-  <script>
-    // The section must not be in the banner.js file because it can create a quick flash.
-
-    if (localStorage.getItem('{{ site.Params.banner.key | default `banner-closed` }}')) {
-      document.documentElement.style.setProperty("--hextra-banner-height", "0px");
-      document.documentElement.classList.add("hextra-banner-hidden");
-    }
-  </script>
+  {{- if hugo.IsProduction -}}
+  {{- $scripts = $scripts | minify | fingerprint -}}
+  {{- end -}}
+  <script src="{{ $scripts.RelPermalink }}" integrity="{{ $scripts.Data.Integrity }}"></script>
 
   <!-- Math engine -->
   {{ $noop := .WordCount -}}