This cookiecutter is based on the upstream JupyterLab Extension Cookiecutter: https://github.com/jupyterlab/extension-cookiecutter-ts
Install cookiecutter with:
pip install cookiecutter
Use cookiecutter to generate a package, following the prompts to fill in the name and authorship of your new JupyterLab extension.
cookiecutter https://github.com/jupyterlite/serverlite-cookiecutter-ts