add script to run

index.js

+var express = require('express');
+var app = express();
+
+app.get('/', function (req, res) {
+   res.send('Hello World');
+})
+
+var server = app.listen(8081, function () {
+
+  var host = server.address().address
+  var port = server.address().port
+
+  console.log("Ung dung Node.js dang lang nghe tai dia chi: http://%s:%s", host, port)
+
+})
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