Static CMS v4 (#246)

- Static CMS v4
- switch from jsdelivr to unpkg due to performance issues
- custom themes
- preset view_group

Reviewed-on: #246

static/admin/config/themes.js

@@ -0,0 +1,25 @@
+const GCGThemeDark = {
+  name: "GCG.Dark",
+  extends: "dark",
+  primary: {
+    main: "#ffbc3b",
+    contrastColor: "#4b4b4b",
+  },
+  background: {
+    main: "#1a1a37",
+    dark: "#13132d",
+  },
+};
+
+const GCGThemeLight = {
+  name: "GCG.Light",
+  extends: "light",
+  primary: {
+    main: "#1a1a37",
+  },
+  background: {
+    dark: "#f1f3f5",
+  },
+};
+
+export { GCGThemeDark, GCGThemeLight };