Added a guide for Windows users. (#12)

Co-authored-by: David Anderson <david@alpinegizmo.com>

operations-playground/README.md

@@ -36,6 +36,11 @@ docker-compose up -d
 
 You can check if the playground was successfully started by accessing the WebUI of the Flink cluster at [http://localhost:8081](http://localhost:8081).
 
+#### for Windows Users
+
+If you get the error "Unhandled exception: Filesharing has been cancelled", you should configure file sharing in Docker Desktop before starting.
+In Settings > Resources > File Sharing, add the operations-playground/conf directory.
+
 ### Stopping the Playground
 
 To stop the playground, run the following command