update Sponsor

Author: doghappy

README.md

@@ -343,3 +343,5 @@ SocketIOClient v2.2.0 makes `System.Text.Json` the default JSON serializer. If y
 - [darrachequesne](https://github.com/darrachequesne) ([socket.io team](https://github.com/socketio/socket.io)), [500 USD](https://opencollective.com/socketio/expenses/44350), June 2021
 - [darrachequesne](https://github.com/darrachequesne) ([socket.io team](https://github.com/socketio/socket.io)), [500 USD](https://opencollective.com/socketio/expenses/46822), July 2021
 - [darrachequesne](https://github.com/darrachequesne) ([socket.io team](https://github.com/socketio/socket.io)), [500 USD](https://opencollective.com/socketio/expenses/49090), August 2021
+- [darrachequesne](https://github.com/darrachequesne) ([socket.io team](https://github.com/socketio/socket.io)), [500 USD](https://opencollective.com/socketio/expenses/51776), September 2021
+- [darrachequesne](https://github.com/darrachequesne) ([socket.io team](https://github.com/socketio/socket.io)), [500 USD](https://opencollective.com/socketio/expenses/54770), October 2021