add bootstrap with npm code example
Example 1: npm bootstrap
npm install bootstrap@latest
Example 2: bootstrap npmjs
npm i bootstrap@5.0.0-alpha1
Example 3: ./node_modules/bootstrap/dist/js/bootstrap.bundle.js
npm i --save-dev bootstrap@next bootstrap-loader tether jquery
Example 4: ./node_modules/bootstrap/dist/js/bootstrap.bundle.js
npm install --save resolve-url-loader --dev