The part of the billet project to generate assets based on webpack and independent from ruby on rails.
To add assets to your rails project, run:
bin/rails app:template LOCATION=https://raw.githubusercontent.com/cimon-io/billet-isolated-assets/master/.billet.rb
Separate command bin/assets or run it from the subfolder assets via command yarn watch. To build for production run bin/assets compile or cd assets && yarn build.