Where else should be we publish or notify about advisories?

## Summary

We have the site, (soon) an atom feed, and osv.dev with whatever downstream notification capabilities it has.

But we received a [question](https://github.com/haskell/security-advisories/pull/157#issuecomment-1988372934) about whether we publish in discourse, newletters, etc.

Let's discuss at the next SRT meeting and make a plan. It may involve community engagement to decide what will have the biggest impact.

Review the existing site, the planned Atom feed, and osv.dev's downstream notification capabilities, along with the referenced question. Discuss additional channels such as Discourse or newsletters at the next SRT meeting; done means the team has an agreed publication and notification plan.

Written by the indexing model from the issue text.