If you're creating your own project, we recommend using @open-wc's project generator, which will get you started in an environment similar to this repository. @open-wc also uses Lit for building components and @web/test-runner for their testing framework, making it easier for us to troubleshoot and reproduce any issues you run into, as well as reducing the amount of changes to make to your code if you decide to contribute your work to our library. For specific information on how to configure your @open-wc project, click here.