Adding a Coffee badge

Author: x0rz

README.md

@@ -35,3 +35,7 @@ Only use this as an extra source of entropy if you wish.
 License
 ----
 GNU GPLv3
+
+If this tool has been useful for you, feel free to thank me by buying me a coffee
+
+[![Coffee](https://www.buymeacoffee.com/assets/img/custom_images/orange_img.png)](https://buymeacoff.ee/x0rz)