Consider adding a license

Considering the files in this repository are meant to be directly copied into a project, some people might have concerns about the project having no license, since it's not clear whether there are any limitations.

Reference: https://choosealicense.com/no-permission/

No specific files or tests are named. Start by reviewing the repository's Gradle scripts and the referenced no-permission guidance, then determine which licensing approach maintainers want; done means the repository's licensing terms are explicitly documented for the files intended for direct copying.

Written by the indexing model from the issue text.