Usage section of readme doesn't describe usage.
There's a usage section in the readme but it doesn't actually say what to do other than yarn install. There's no start script, what is the user supposed to be running? There's a gulpfile, what is that for? Does the user have to run gulp before anything else? Or just yarn install?
As mentioned in the readme:
This app showcase a wide range of popular packages, and show that Plug'n'play has no issue working with them.
So basically, pretty much all those scripts are just typical tools that you'd find in a regular app. Running gulp will build the webapp, running yarn webpack as well, running yarn serve will serve the app on the port 8080, running yarn rollup will build a library exposing fibonnacci, etc ...
The only piece that matters is yarn install, really :)