CC0 1.0 Universal (CC0 1.0) Public Domain Dedication

The person who associated a work with this deed has dedicated the work to the
public domain by waiving all rights to the work worldwide under copyright law,
including all related and neighboring rights, to the extent allowed by law.

You can copy, modify, distribute and perform the work, even for commercial
purposes, all without asking permission.

Full text: https://creativecommons.org/publicdomain/zero/1.0/legalcode
