add instructions for windows for prox keys script

proximity_keys.py

@@ -1,4 +1,9 @@
 #!/usr/bin/env python3
+
+# Needs https://github.com/google/bumble on Windows
+# See https://github.com/google/bumble/blob/main/docs/mkdocs/src/platforms/windows.md for usage.
+# You need to associate WinUSB with your Bluetooth interface. Once done, you can roll back to the original driver from Device Manager.
+
 import sys
 import asyncio
 import argparse