docs: typo (serialport#2613)

Author: caoxiemeihao

README.md

@@ -84,4 +84,4 @@ Support this project by becoming a sponsor. Your logo will show up here with a l
 <a href="https://opencollective.com/serialport/sponsor/6/website" target="_blank"><img src="https://opencollective.com/serialport/sponsor/6/avatar.svg"></a>
 <a href="https://opencollective.com/serialport/sponsor/7/website" target="_blank"><img src="https://opencollective.com/serialport/sponsor/7/avatar.svg"></a>
 <a href="https://opencollective.com/serialport/sponsor/8/website" target="_blank"><img src="https://opencollective.com/serialport/sponsor/8/avatar.svg"></a>
-<a href="https://opencollective.com/serialport/sponsor/9/website" target="_blank"><img src="https://opencollective.com/serialport/sponsor/9/avatar.svg"></a> --> -->
+<a href="https://opencollective.com/serialport/sponsor/9/website" target="_blank"><img src="https://opencollective.com/serialport/sponsor/9/avatar.svg"></a> -->