Update docs to reflect VITE env variable naming

Author: Mansi2007275

docs/Installation.md

@@ -134,8 +134,8 @@ npm install
 ```bash
 cp .env.example .env
 ```
-Ensure `REACT_APP_API_URL` points to your backend URL (e.g., `http://localhost:5000`).
-
+<!-- Ensure `REACT_APP_API_URL` points to your backend URL (e.g., `http://localhost:5000`). -->
+Ensure `VITE_REACT_APP_API_URL` points to your backend URL (e.g., `http://localhost:5000`).
 #### Start the react frontend application
 ```bash
 npm start