I’m not a big fan of boilerplate either so I use ParcelJS. You just have to create your index.html file, add your script (can also be TypeScript, the just us JS as an example) and the call parcel index.html from the command line and it will bundle it all and start a web server for you to test with.
For multiple files all you have to do is add a
require('./path/to/my-file.js')
or
import Object from 'my-file.js
and Parcel will find all the files you referenced and bundle them into one. Super easy to use.