A yeoman generator that integrates with the polymer cli to spin up polymer3 components
npm i -g generator-polymer-init-polymer-3-element
or
git clone https://github.com/matteo-hertel/generator-polymer-init-polymer-3-element
cd generator-polymer-init-polymer-3-element
yarn
npm link
mkdir test-element
cd test-element
polymer init
once the process is completed a simple yarn dev will open the browser and the new element will render on the page!
You're more then welcome to contribute to the generator, in the future an official one will be released and by no means this will be as polished as anything the polymer team will release