Biff v1.8.0 + moving to github discussions

Announcement post.

I’ve updated the links on biffweb.com so they point to GitHub Discussions as the recommended non-Slack place for asking questions. I figure that’d be more convenient for people since most people using Biff will already have a github account. It does introduce some lock in: if people join this forum, I can potentially migrate everyone to a new, better forum in the fewer if one becomes available. Not so with Github. But it’s not like this forum is very active anyway, so the lock-in cost isn’t much.