Few general code quality improvement suggestions

[JasonShin]

1. requirements.txt Add a requirements.txt for dependencies such as Tensorflow with an exact required version

2. black linting/formatting Add a Black formatting configuration to ensure code quality https://github.com/psf/black

3. License Add a LICENSE file

4. Don't put actual initiation code under under if __name__ == '__main__':, instead you should:

def main():
    consts.load_config('../resource/config.json')
    app = QApplication(sys.argv)

    engine = QQmlApplicationEngine()
    main_window = gui.MainWindow(engine)
    
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()