docs: update broken React badge

Replace the broken React badge with a valid Shields.io badge that correctly renders and links to the official React website. No functional changes.

Author: udaycodespace

README.md

@@ -18,7 +18,7 @@
 
 [![MongoDB](https://img.shields.io/badge/MongoDB-database-47A248?style=for-the-badge&logo=mongodb&logoColor=white)](https://www.mongodb.com)
 [![Express](https://img.shields.io/badge/Express-v4.18.2-000000?style=for-the-badge&logo=express&logoColor=black)](https://expressjs.com)
-[![React](https://img.shields.io/badge/React-v18.2.0-61DAFB?style=for-the-badge&logo=react&logoColor=white)](https://react.dev)
+[![React](https://img.shields.io/badge/React-20232A?style=for-the-badge&logo=react&logoColor=61DAFB)](https://react.dev)
 [![Vite](https://img.shields.io/badge/Vite-v4.4.5-646CFF?style=for-the-badge&logo=vite&logoColor=white)](https://vitejs.dev)
 [![License: MIT](https://img.shields.io/badge/License-MIT-F59E0B?style=for-the-badge)](LICENSE)
 [![Status](https://img.shields.io/badge/Status-Local_Development-orange?style=for-the-badge)](#-deployment)