[LightDM] Moving mailing list from freedesktop.org infrastructure

[Adam Nielsen]

> > > Google Groups are still a thing. Seems like it might be a good middle ground between a modern forum and a mailing list.  
> > 
> > +1 for Google Groups.
> 
> groups.io is even better.  And is not part of "Big Brother Google".

If it's a public group then it doesn't really matter whether it's
hosted by "big brother" or not, since big brother will see it anyway
wherever it's located.

I had a look at groups.io and it does seem pretty good.  It looks like
you can't get an RSS feed of new topics/threads (only a feed of
individual messages) so Google Groups is a bit more flexible for RSS
users, but it does seem to work quite well in other respects.

Looks like you only need an account to use the web interface, which has
both threaded views and a straight list of messages.  Apparently you
can "mute" individual threads which could be useful on some lists,
although it doesn't look like this would affect the RSS feed as the URL
is a shared one and not user-specific (although I haven't joined a
group yet, maybe you get your own RSS URL once you join a group?)

It's certainly faster to access than Google's offering and it's a bit
clearer about how to join the group and manage your subscription, so
I would be happy to use groups.io as well.  It does look like it has a
more enthusiastic development team behind it and is probably a better
fit for an open source project.

Cheers,
Adam.