You'll need a GitLab.com account before running npm install. Once you signed up, let us know the username so we can give you access.
Luma includes a modern development workflow based on Webpack and laravel-mix which compiles Sass, ES6 JavaScript, handles production builds, watchers, multiple CSS themes and more. This entire workflow is contained into an installable package named theme-mix.
The download package does not include any vendor libraries. To install all the dependencies, run:
npm run install