Updated the configuration setup docs.

Figured out that need to just add MONGODB_URI to .env if only need to provide URI.

docs/content/1.getting-started/1.setup.md

@@ -49,3 +49,8 @@ export default defineNuxtConfig({
   },
 })
 ```
+If you want to configure only the `uri` just add `MONGODB_URI` in your `.env` file.
+
+```env
+MONGODB_URI=YOUR_MONGO_URI
+```