Creating a library
When choosing which type of project to create with the CLI, choose Library instead of Pack. This will provide a basic template for you to work with. You can explore existing sandstone libraries here and here.
Once you are ready to publish your library, create an npm registry account if you haven't already, and follow the online guides on publishing your library with (p)npm manually, or provide an npm token in your github repository secrets to utilize the included GitHub Action.