docs: udpate README

README.md

@@ -126,3 +126,25 @@ This implementation is basically a port to Rust from <https://gist.github.com/ca
 
 - It does not use magic numbers (explicit enum for states).
 - It prints non UTF-8 string in hexadecimal.
+
+I also want to thank [@da2ce7](https://github.com/da2ce7) for his feedback and review that has improved this project significantly.
+
+## License
+
+**Copyright (c) 2023 The Torrust Developers.**
+
+This program is free software: you can redistribute it and/or modify it under the terms of the [GNU Affero General Public License][AGPL_3_0] as published by the [Free Software Foundation][FSF], version 3.
+
+This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the [GNU Affero General Public License][AGPL_3_0] for more details.
+
+You should have received a copy of the *GNU Affero General Public License* along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+Some files include explicit copyright notices and/or license notices.
+
+### Legacy Exception
+
+For prosperity, versions of Torrust Tracker that are older than five years are automatically granted the [MIT-0][MIT_0] license in addition to the existing [AGPL-3.0-only][AGPL_3_0] license.
+
+[AGPL_3_0]: ./docs/licenses/LICENSE-AGPL_3_0
+[MIT_0]: ./docs/licenses/LICENSE-MIT_0
+[FSF]: https://www.fsf.org/