Missing LICENSE.md

[Gabriel Dougherty]

Hi, do you mind adding a license to this repository? Without a license, you retain all rights to this repository. https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/licensing-a-repository

[ZH王]

Maybe public domain in law speaking?
It is short enough.
Maybe I'm kidding.

[Nicolas Herbaut]

Fixed