Add documentation for Bang & Olufsen device triggers

source/_integrations/bang_olufsen.markdown

@@ -250,6 +250,16 @@ data:
 
 WebSocket notifications received from the device are fired as events in Home Assistant. These can be received by listening to `bang_olufsen_websocket_event` event types, where `device_id` or `serial_number` can be used to differentiate devices.
 
+
+### Device triggers
+Device triggers for most of the physical controls are available for all devices.
+
+Device triggers for the [Beoremote One](https://www.bang-olufsen.com/en/dk/accessories/beoremote-one) are supported. Enter the submenus __Control__ or __Light__ by pressing __Right__ and trigger any of the renamable functions. Additionally, the __Control__ and __Light__ submenus can be entered by pressing __Select__, which will make most of the buttons trigger an event. Each compatible button press will send a __KeyPress__ and a __KeyRelease__ event, and therefore also a __KeyPress__ and a __KeyRelease__ device trigger.
+
+{% tip %}
+Enable debug logging to see what IDs are associated with the different functions.
+{% endtip %}
+
 ### Getting Deezer URIs
 
 To find Deezer playlist, album URIs, and user IDs for Deezer flows, the Deezer website has to be accessed. When navigating to an album, the URL will look something like: <https://www.deezer.com/en/album/ALBUM_ID>, and this needs to be converted to: `album:ALBUM_ID` and the same applies to playlists, which have the format: `playlist:PLAYLIST_ID`.