refactor: remove frontend, move JSONs to json/ top-level

- Archive frontend to community-scripts/ProxmoxVE-Frontend-Archive
- Move frontend/public/json/ -> json/
- Update workflow paths in 5 actions:
  - update-versions-github.yml
  - update-json-date.yml
  - push-json-to-pocketbase.yml
  - delete-pocketbase-entry-on-removal.yml
  - autolabeler.yml
- Remove frontend-cicd.yml (no longer needed)
- Clean up .gitignore (remove frontend-specific entries)

json/turnkey.json

@@ -0,0 +1,44 @@
+{
+  "name": "TurnKey",
+  "slug": "turnkey",
+  "categories": [
+    2
+  ],
+  "date_created": "2024-05-02",
+  "type": "turnkey",
+  "updateable": false,
+  "privileged": false,
+  "interface_port": null,
+  "documentation": null,
+  "website": "https://www.turnkeylinux.org/",
+  "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons@main/webp/turnkey-linux.webp",
+  "config_path": "",
+  "description": "TurnKey LXC Appliances is an open-source project that provides a collection of free, ready-to-use virtual appliances and installation images for various software applications and services. These appliances are pre-configured and come with all the necessary software and settings to simplify deployment and management. The goal of TurnKey Linux is to make it easier for users to set up and run popular software applications without the need for extensive manual configuration.",
+  "install_methods": [
+    {
+      "type": "default",
+      "script": "turnkey/turnkey.sh",
+      "resources": {
+        "cpu": null,
+        "ram": null,
+        "hdd": null,
+        "os": null,
+        "version": null
+      }
+    }
+  ],
+  "default_credentials": {
+    "username": null,
+    "password": null
+  },
+  "notes": [
+    {
+      "text": "The script creates a `*.creds` file in the Proxmox root directory with the password of the newly created TurnKey LXC Appliance.",
+      "type": "info"
+    },
+    {
+      "text": "Retrieve Password: `cat turnkey-name.creds`",
+      "type": "info"
+    }
+  ]
+}