Initial commit: Grav CMS setup with HTML reference material

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

plugins/flex-objects/blueprints/flex-objects/pages.yaml

@@ -0,0 +1,22 @@
+title: Pages (Admin)
+description: Manage your Grav Pages in the new Flex Pages admin. This allows you to use Flex Pages only in Admin plugin, while still using the old pages in the frontend.
+type: flex-objects
+
+extends@:
+  type: pages
+  context: blueprints://flex
+
+form:
+  fields:
+    lang:
+      type: hidden
+      value: ''
+
+    tabs:
+      fields:
+        security:
+          type: tab
+          title: PLUGIN_ADMIN.SECURITY
+          import@:
+            type: partials/security
+            context: blueprints://pages