Merge pull request #10 from var2p/patch-1

add unambigious license badge

Author: minhnq1-apero

README.md

@@ -229,7 +229,9 @@ maintenance, new features, and keeping the app free.
 
 ## License
 
-This project is licensed under the **GNU License**.
+[![GPL-3.0-only](https://img.shields.io/badge/License-GPL--3.0--only-blue.svg)](https://spdx.org/licenses/GPL-3.0-only.html)
+
+This project is licensed under the **GNU General Public License v3.0 only (GPL-3.0-only)**.
 You are free to use, modify, and distribute it.
 See the full [LICENSE](LICENSE) file for details.