🚀 [Feature] `@all` Mention for Network Admins to Inform all Network Users by a Post

[Tirokk]

🚀 Feature

@all Mention for Network Admins to Inform all Network Users by a Post.

Todo

Only for network admins:

• webapp – editor:
  • add the @all mention to the mention menu:
  • add it at the beginning of the menu and seperate it by a seperation line
  • if the user choses @all it is placed as a link in the editor:
  • ?what the link and id(?) shall be?
• backend:
  • if the @all mention is in the post content:
  • send all users a notification:
    • ?sender is the admin?

Add to top of menu with seperator line:

[Tirokk]

Was closed by merging a similar branch, so I reopen.