add livekit

howto/conference.md

@@ -747,6 +747,8 @@ out of scope, or have come up after the evaluation was performed:
    20-40 participants for meetings, 400+ participants for lectures, no
    simulcasting, no federation
  * [Lightspeed](https://github.com/GRVYDEV/Project-Lightspeed) - realtime streaming
+ * [Livekit](https://meet.livekit.io/) - WebRTC, SFU, based on Pion, [used by Matrix in
+   Element Call](https://element.io/blog/element-call-beta-3/)
  * [Mediasoup](https://mediasoup.org/) - backend framework considered
    by BBB developers
  * [Medooze](http://medooze.com/) - backend framework considered