chore: Update appsettings.json

Author: l4rm4nd

examples/gzctf/appsettings.json

@@ -31,6 +31,12 @@
     "SiteKey": "<Your SITE_KEY>",
     "SecretKey": "<Your SECRET_KEY>"
   },
+  "Registries": {
+    "ghcr.io": {
+      "UserName": "your-username",
+      "Password": "ghp_..."
+    }
+  },  
   "ForwardedOptions": {
     "ForwardedHeaders": 7,
     "ForwardLimit": 1,