Use Bootstrap via npm
Use Bootstrap via npm ~15 mins
Prerequisite: Create Node Project
    mkdir project1
cd project1
npm init -y
Task 1.1: Install Bootstrap
  npm install bootstrap
Task 1.2 : Check node_modules folder for bootstrap
  node_modules/dist/css/bootstrap.min.css
node_modules/dist/js/bootstrap.min.js
Task 1.3: Refer bootstrap in html
    <head>    
<link rel="stylesheet" href="node_modules/bootstrap/dist/css/bootstrap.min.css">
<script src="node_modules/bootstrap/dist/js/bootstrap.min.js"> </script>
</head>
Task 1.4: Install Jquery ( Bootstrap internally uses jquery )
    npm i jquery
    <head>    
<link rel="stylesheet" href="node_modules/bootstrap/dist/css/bootstrap.min.css">
<script src="node_modules/jquery/dist/jquery.min.js"></script>
<script src="node_modules/bootstrap/dist/js/bootstrap.min.js"> </script>
</head>

Note: Jquery must be included before bootstrap.min.js