[J-core] libera.chat IRC.

[Rob Landley]

The #j-core channel on Freenode is moving to #jcore on libera.chat. (See
https://lwn.net/Articles/856543/ and
https://boingboing.net/2021/05/19/freenode-irc-staff-quit-after-new-owner-seizes-control.html
for backstory.)

We waited a few days to see if more people were moving to oftc than to
libera.chat (which is the one the fleeing volunteers set up, sort of an
etherial->wireshark kind of thing), and then switched to libera.

One advantage of this is we can actually register the channel, which we couldn't
at freenode (#jcore with no dash was registered-but-abandoned years ago, and
their system can't register a channel with a dash it it because they use that
for "namespaces".)

Alas the downside of not having properly registered the old channel is I can't
change the /topic without help from an admin, and all the admins quit to go to
libera.chat already. So I've updated the website's nav bar and am posting it here.

I'll try to log in and hang out there more often on libera than I did on
freenode. :)

Rob