fix: npm start instead of ui5 serve

Author: lucamueller01

ex0/readme.md

@@ -54,7 +54,7 @@ Finally, we will serve the project using ui5.
 - In the terminal or command prompt at our project's root directory, run the following command:
 
 ```bash
-ui5 serve
+npm start
 ```
 
 This command will start a development server for our project. You can access the development server at http://localhost:8080/index.html and check out the running application! 🚀