Mention circle in markdown documents

Is your feature request related to a problem? Please describe.
I use Nextcloud in an association and we had the idea to use circles to organise who has which roles. It would be really nice if we could mention the circles in a markdown document as you can with single people, e.g. it is relevant for the whole circle/role or if someone in the circle should do something, but it is irrelevant who exactly does it.

Describe the solution you'd like
You can just mention circles as any singular person. Everyone in this circle receives a notification.

Describe alternatives you've considered
If it is easier to implement it with groups, this might also be a first idea. But since groups are only manageable by (group) admins, I think it should be possible to mention circles in the end as well.

Additional context
Maybe there should be a setting that disables this feature so that not everyone can mention a lot of people simultaneously.

The issue names no files, tests, or entry points. Start by locating the existing single-person mention behavior in Markdown documents, then determine how circle membership, notifications, and the proposed opt-out or permission setting should work; done means circles can be mentioned and their members are notified.