revert c4206b7d341c9f28285efa0582ab0271ddfeaa49

revert 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/schulchronik.js

@@ -7,7 +7,6 @@ import {
   StatsCollection,
   SuperhaufenCollection,
 } from "./collections/index.js";
-import { GCGThemeDark, GCGThemeLight } from "./themes.js";
 
 const config = {
   backend: {
@@ -39,13 +38,6 @@ const config = {
     clean_accents: true,
     sanitize_replacement: "-",
   },
-  theme: {
-    include_built_in_themes: false,
-    themes: [
-      GCGThemeDark,
-      GCGThemeLight
-    ]    
-  },
   collections: [
     ChronikjahreCollection,
     SuperhaufenCollection,