UDP Sound Sync protocol (#320)

* Info about the UDP Sound Sync protocol v2; clarify that the UDP (multicast) port is user-configurable; iclude link to WLED-MM pages for more information.
* Mention WARLS alongside "udp realtime"

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Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>
Co-authored-by: Frank Möhle <91616163+softhack007@users.noreply.github.com>

Author: 3 people

docs/interfaces/udp-realtime.md

@@ -21,7 +21,14 @@ Select one of the UDP options in the device configuration wizard.
 Supported in latest master and will be available in WLED 0.10.1.
 Please set the WLED broadcast UDP port to 65506 in Sync settings to enable receiving TPM2.NET data.
 
-### UDP Realtime
+### UDP Sound Sync (v2, v2+)
+
+This feature acts as a sound input and accepts pre-processed sound data on UDP port 11988 (user configurable). 
+Generating and sending this data can be done in multiple ways: 
+there is a [Windows application](https://github.com/Victoare/SR-WLED-audio-server-win) or a lower-level [C library](https://github.com/netmindz/WLED-sync). 
+Learn more about this feature in the [documentation of the MM-fork](https://mm.kno.wled.ge/soundreactive/sync/), where it was originally implemented.
+
+### UDP Realtime (v1) and WARLS
 
 Additionally, WLED offers a way to directly drive the connected LEDs via UDP. The protocol is referred to as WLED [Audio-Reactive-Led-Strip](https://github.com/scottlawsonbc/audio-reactive-led-strip) (WARLS), since the support of that project was its primary goal. However, it can also be used for other realtime applications like an ambilight.