Add license section to README

Include license information in README.md for clarity and compliance.

Changes:
- Add ## License section with GPLv3 reference

README.md

@@ -40,4 +40,8 @@ This will set up the virtual environment, systemd services, and provide post-ins
 
 - Logs: `journalctl --user -u email_forwarder.service`
 - Test: `source venv/bin/activate && python -m email_forwarder`
-- Timezone issues: Adjust UTC offset in script if needed.
+- Timezone issues: Adjust UTC offset in script if needed.
+
+## License
+
+This project is licensed under the GPLv3 License - see the [LICENSE](LICENSE) file for details.