Update README to reflect correct usage of setup script with project n…

…ame placeholder

README.md

@@ -34,7 +34,7 @@ Create a new React application using the Edge-first Starter Kit:
 ```sh
 bun create edgefirst-dev/starter <my-app>
 cd my-app
-bun run setup [app-name]
+bun run setup <my-app>
 ```
 
 The `setup` script will ask for your project name, and other information to configure the project locally and on Cloudflare.