Simply require the theme in your Papyrus project:
composer require soma/papyrus-theme
The theme is built using parcel. Install all modules using npm/yarn:
npm install
Then simply run npm run dev
for a development build that updates on file changes. Or run npm run release
in order to build it for production.
The build system is using parcel.js and relative paths to theme assets - as you can see in the commands specified in the package.json file. You might want to change the public urls to fit your environment and setup.
MIT