[webkit-help] Add Web Bluetooth API to WebKit Feature Status

[François Beaufort 🇫🇷]

It would be nice to add the experimental Web Bluetooth API to WebKit
Feature Status.
This API is for communicating with Bluetooth Low Energy devices as a
GATT Client. See https://webbluetoothcg.github.io/web-bluetooth/

For info, here are the other browser vendor status pages:
- https://www.chromestatus.com/features/5264933985976320
- https://dev.windows.com/en-us/microsoft-edge/platform/status/webbluetooth
- https://mozilla.github.io/platatus/#web_bluetooth