nextExplorer: fix json

frontend/public/json/nextexplorer.json

@@ -14,7 +14,7 @@
   "website": "https://github.com/vikramsoni2/nextExplorer",
   "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons@main/webp/nextexplorer.webp",
   "config_path": "/etc/nextExplorer/.env",
-    "description": "",
+  "description": "Self-hosted file access for teams, homelabs, and agencies with a refined interface.",
   "install_methods": [
     {
       "type": "default",
@@ -28,6 +28,10 @@
       }
     }
   ],
+  "default_credentials": {
+    "username": null,
+    "password": null
+  },
   "notes": [
     {
       "text": "Bind mount your volume(s) in the `/mnt` directory",