Explain magic number in BLE advertisement

This code snippet threw me for a loop trying to understand what "961" meant. After a good amount of digging I found the appearance numbers in the bluetooth spec, to see that 961 is 0x03C1 or "keyboard".

Add a comment to hopefully guide future readers.

Author: nivekmai

CPB_Keybutton_BLE/code.py

@@ -37,6 +37,8 @@
 device_info = DeviceInfoService(software_revision=adafruit_ble.__version__,
                                 manufacturer="Adafruit Industries")
 advertisement = ProvideServicesAdvertisement(hid)
+# Advertise as "Keyboard" (0x03C1) icon when pairing
+# https://www.bluetooth.com/specifications/assigned-numbers/
 advertisement.appearance = 961
 scan_response = Advertisement()
 scan_response.complete_name = "CircuitPython HID"