moved css module example to component exmaple

client/src/components/HelloWorld.jsx

@@ -1,7 +0,0 @@
-import React from 'react';
-
-function HelloWorld() {
-  return <div>Hello World - React.js</div>;
-}
-
-export default HelloWorld;

client/src/components/HelloWorld/HelloWorld.jsx

@@ -0,0 +1,8 @@
+import React from 'react';
+import styles from './style/HelloWorld.module.css'; // CSS module -> className={styles.App} (AKA styled components)
+
+function HelloWorld() {
+  return <div className={styles.HelloWorld}>Hello World - React.js</div>;
+}
+
+export default HelloWorld;

client/src/components/HelloWorld/style/HelloWorld.module.css

@@ -0,0 +1,6 @@
+.HelloWorld {
+  width: 100%;
+  min-height: 100vh;
+  display: grid;
+  place-items: center;
+}