zeroconf / mdns-sd support

[DrPyser]

Hi. Thanks to all contributors for providing this great software.

I'm interested in benefiting from a zeroconf / mdns-based registrar discovery in baresip.
The use case is to minimize configuration overhead for baresip-as-a-user-agent, and benefit from transparent load-balancing / failover offered by DNS SRV records in a local domain using mdns.

I saw that an avahi module was implemented and included but was removed in 2020 for lack of maintenance & evidence of use.
#293
#901

(quick note, I don't see any notice to that effect in the Changelog).

I'll try and recover that module's code to see if it is still functional. Is there any chance that is the case without too much changes, or advice towards that end?
Is there any chance of plans to bring back such zeroconf/mdns-sd support in baresip one way or another?
If not that's alright, I'll see what I can do on my end.

Thanks for the good work!

[cspiel1]

Not sure. I think a PR would be welcome.