Update README.md

Author: yushulx

README.md

@@ -1,6 +1,6 @@
 # Welcome to Dynamsoft Barcode Reader - Python Edition
 [![Current version number](https://img.shields.io/pypi/v/dbr?color=orange)](https://pypi.org/project/dbr/)
-[![Supported Python versions](https://img.shields.io/badge/python-3.6%20%7C%203.7%20%7C%203.8-blue)](https://www.python.org/downloads/)
+[![Supported Python versions](https://img.shields.io/badge/python-3.6%20%7C%203.7%20%7C%203.8%20%7C%203.9-blue)](https://www.python.org/downloads/)
 [![PyPI downloads](https://img.shields.io/pypi/dm/dbr)](https://pypistats.org/packages/dbr)
 
 ![Dynamsoft](https://dynamsoft.github.io/styleguide/assets/img-icon/logo-dynamsoft-whiteBg-190x47.png "Dynamsoft")  | ![dbr](https://dynamsoft.github.io/styleguide/assets/img-icon/logo-dbr-88x88.png "dbr")