incorporate improvement suggestions

README.md

@@ -116,7 +116,7 @@ $ mvn spring-boot:run
 2018-04-11 09:35:49.853  INFO 88567 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization completed in 15 ms
 ```
 
-Then, in another window, fetch `http://localhost:8080/api/hello` with curl: 
+Then, in another window, fetch http://localhost:8080/api/hello with curl or your web browser: 
 
 ```
 $ curl http://localhost:8080/api/hello
@@ -126,6 +126,10 @@ Hello, the time at the server is now Wed Apr 11 09:38:19 CEST 2018
 That's great, we now have a rest service in Spring Boot up and running!
 
 ## Adding React
+
+This section uses the tool [npx](https://medium.com/@maybekatz/introducing-npx-an-npm-package-runner-55f7d4bd282b), 
+which is included with newer versions of `npm`. 
+
 ```
 npx create-react-app frontend
 

frontend/src/App.js

@@ -4,23 +4,20 @@ import './App.css';
 
 class App extends Component {
 
-    getHello = () => {
+    state = {};
+
+    componentDidMount() {
+        setInterval(this.hello, 250);
+    }
+
+    hello = () => {
         fetch('/api/hello')
             .then(response => response.text())
             .then(message => {
                 this.setState({message: message});
             });
     };
 
-    constructor() {
-        super();
-        this.state = {};
-    }
-
-    componentDidMount() {
-        setInterval(this.getHello, 250);
-    }
-
     render() {
         return (
             <div className="App">