The documentation is available online here:

https://cartzilla.createx.studio/docs/dev-setup.html OR Offline: inside Cartzilla/dist/docs

Theme Installation Steps:

1. Install Node.js and Npm (Node Package Manager) https://nodejs.org/en/
2. Run npm install in your terminal to install all project dependencies
3. After the installation is completed run gulp to launch the project. It should automatically opens Finder homepage in your browser (http://localhost:3000/)

For more details see the documentation that comes with the theme.