config/media/sndio: remove

Having this documentation makes it seem like its "supported" and users
install or want to use it for some reason while its pretty incomplete
and only supported by a handful of programs for which some require
patches that I don't think I would maintain if they ever break.

src/SUMMARY.md

@@ -59,7 +59,6 @@
       - [ALSA](./config/media/alsa.md)
       - [PipeWire](./config/media/pipewire.md)
       - [PulseAudio](./config/media/pulseaudio.md)
-      - [sndio](./config/media/sndio.md)
    - [Bluetooth](./config/bluetooth.md)
    - [TeX Live](./config/texlive.md)
    - [External Applications](./config/external-applications.md)

src/config/media/index.md

@@ -4,7 +4,8 @@
 
 To setup audio on your Void Linux system you have to decide if you want to use
 [PulseAudio](./pulseaudio.md), [PipeWire](./pipewire.md) or just
-[ALSA](./alsa.md).
+[ALSA](./alsa.md). Sndio is also available, but is neither supported nor
+recommended.
 
 Some applications require PulseAudio, especially closed source programs, but
 [PipeWire](./pipewire.md) provides a drop-in replacement for PulseAudio.