Among other things, this contains the "collapsable reply threads" feature
which makes it behave similar to slack.
Also, after spending thirty minutes or so attempting to teach niv that
it should really only fetch the tag "5.37.0" from the mattermost-server
repository and not any other commit, branch, or similar (there is a
"release-5.37" branch, but that seems to be for active development), I
have temporarily given up on it and typed in the urls manually.
Unfortunately, this means that any kind of `niv update` will now break
things. If anyone knows how to use niv correctly for this please patch
this; otherwise I guess we can extract mattermost out from niv again.
note that this ALSO disables the security alert features of mattermost [1],
which would send us alerts in case of security updates for our current
mattermost version. I have disabled it since it would send information
about our instance (including e.g. the current number of active users) to
mattermost every 24 hours.
Since we now essentially maintain our own set of mattermost packages, I
recommend at least some of us subscribe to the mattermost release blog [2],
and manually update the mattermost sources in `/pkgs/mattermost` as required
(I have done so already). The release blog is also available as an rss feed [3].
[1] https://docs.mattermost.com/administration/telemetry.html#security-update-check-feature
[2] https://mattermost.com/blog/category/releases
[3] https://mattermost.com/blog/category/releases/rss
