Outline: Add 'Group' permissions

[aam1r]

Permissions for collections (re: #989) are now based on a per-user basis. A user is explicitly added to collections and that controls what kind of access they have.

It would be pretty powerful to have Group based memberships.

Instead of giving one-off permissions to users to individual collections, the administrator would define Groups. For example:

• Engineering
• Finance
• HR
• Operations
• Marketing, Sales, etc.

The collection permissions would then be granted to the group. This makes it much easier to control permissions for larger teams than having to individually grant permissions to users.

[tommoor]

Hey @aam1r – this project has been started, progress can be followed here: https://github.com/outline/outline/pull/1102