changed README.md

Author: salgum1114

README.md

@@ -40,7 +40,7 @@ Run `npm install react-design-editor` or `yarn add react-design-editor`
 1. Clone this Project with `git clone https://github.com/salgum1114/react-design-editor.git`
 2. Install dependencies with `npm install` or `yarn`
 3. Run the App with `npm start` or `yarn start`
-4. Open your web browser to `http://localhost:8080`
+4. Open your web browser to `http://localhost:4000`
 
 # Screenshots
 ## Image Map Editor