[doc] Add note for playback on iOS devices

docs/outputs/streaming.md

@@ -1,21 +1,47 @@
 # Streaming
 
-You can listen to audio being played by OwnTone by opening this network
-stream address in pretty much any music player:
+The streaming option is useful when you want to listen to audio played by
+OwnTone in a browser or a media player of your choice (see note [^1] and
+[^3]).
 
- [http://owntone.local:3689/stream.mp3](http://owntone.local:3689/stream.mp3)
-   or
- http://SERVER_ADDRESS:3689/stream.mp3
+Moreover, Apple Remote or the web interface can be used to control the
+playback.
 
-This is currently the only way of listening to your audio on iOS devices, since
-Apple does not allow AirPlay receiver apps, and because Apple Home Sharing
-cannot be supported by OwnTone. So what you can do instead is install a
-music player app like VLC, connect to the stream and control playback with
-Remote.
+## Listening to Audio in a Browser
 
-In the speaker selection list, clicking on the icon should start the stream
-playing in the background on browsers that support that.
+To listen to audio being played by OwnTone in a browser, follow these
+steps:
 
-Note that MP3 encoding must be supported by ffmpeg/libav for this to work. If
-it is not available you will see a message in the log file. In Debian/Ubuntu you
-get MP3 encoding support by installing the package "libavcodec-extra".
+1. Start playing audio in OwnTone.
+2. In the web interface, activate the stream in the output menu by clicking
+   on the icon :material-broadcast: next to HTTP Stream.
+   After a few seconds, the audio should play in the background (see note [^2]).
+
+## Listening to Audio in a Media Player
+
+To listen to audio being played by OwnTone in a media player, follow these
+steps:
+
+1. Start playing audio in OwnTone.
+2. In the web interface, activate the stream in the output menu by clicking
+   on the icon :material-broadcast: next to HTTP Stream.
+   After a few seconds, the audio should play in the background.
+3. Copy the URL behind the :material-open-in-new: icon next to HTTP Stream.
+4. Open the copied URL with the media player, e.g., VLC.
+   The URL is usually
+   [http://owntone.local:3689/stream.mp3](http://owntone.local:3689/stream.mp3)
+   or http://SERVER_ADDRESS:3689/stream.mp3
+
+## Notes
+
+[^1]: On iOS devices, the streaming option is the only way of listening to your
+      audio, since Apple does not allow AirPlay receiver apps, and because
+      Home Sharing cannot be supported by OwnTone.
+
+[^2]: On iOS devices, playing audio in the background when the device is locked
+      is not supported in a private browser tab.
+
+[^3]: For the streaming option to work, MP3 encoding must be supported by
+      `libavcodec`. If it is not, a message will appear in the log file.
+      For example, on Debian or Ubuntu, MP3 encoding support is provided by the
+      package `libavcodec-extra`.