Publish security audit and related info

[graphiclunarkid]

We need to

1. Publish the NCC audit report
2. Publish information about which vulnerabilities are fixed.
3. Inform users about remaining vulnerabilities
4. Document how users can mitigate remaining vulnerabilities where possible

[graphiclunarkid]

Just a reminder to @misaakidis to push your latest version of the documentation related to this issue ASAP so that we can pick up where you've left off. Don't bother tidying it up first - we can cope!

[graphiclunarkid]

Related Redmine ticket, with draft NCC report attached, and linking to private issues for each finding we need to address: https://redmine.equalit.ie/redmine/issues/3658

[florianap]

I've added a document for securing bridge nodes to solve some issues: https://github.com/equalitie/ceno/blob/next/doc/secure-bridge.md