Basic hello world index.js

index.js

+const express = require('express');
+
+const app = express();
+
+const port = process.env.PORT || 3000;
+
+
+app.get('/', (req, res) => {
+  res.send('Hello World!');
+});
+
+
+app.listen(port, () => {
+  console.log(`Server is running on port ${port}`);
+});