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/collections/blog.js

@@ -24,12 +24,16 @@ const BlogCollection = {
     field: "type",
     value: "post",
   },
-  view_groups: [
-    {
-      label: "Entwurf",
-      field: "draft",
-    },
-  ],
+  view_groups: {
+    default: "draft",
+    groups: [
+      {
+        name: "draft",
+        label: "Entwurf",
+        field: "draft",
+      },
+    ],
+  },
   sortable_fields: {
     fields: ["date", "title"],
     default: {