Provide a discussion space

Should we use

* a mailing-list (cool)
* a slack (privative and oh so uncool)
* a frama* (https://framasoft.org) discussion space ? https://framaboard.org or https://framateam.org/login (mattermost)
* a zulip https://zulipchat.com (like slack mixed with mail)

You decide

The issue contains no files, tests, or entry points to inspect. Compare the proposed mailing list, Slack, Frama.space options, and Zulip, then determine which discussion space the project should adopt. Done means reaching and recording a decision, but the issue does not define implementation or documentation steps.

Written by the indexing model from the issue text.