I use yarn, but you can just use npm just as well for this. It's just a simple compiler for flat pages. Nothing special, but it makes life so much easier than doing everything inline.
It has the added bonus of being able to serve itself as well with browserSync
So clone the repo into your local folder.
run either of the following commands
yarn
or
npm install
This will install the dependencies you may need.
Once that has completed (potentially about a minute, but can sometimes take longer).
You can fire up the base code with:
npm run start
or
yarn start
This will compile all the scripts and open in your default browser.
There is also a build script in there which is just for building out the files without serving them.
I find it useful for zipping up the files. Just replace start with build with either of the above commands. I used to have a zip file, but find it best to do this manually.