Mailing Group Under Address Book in Sidebar
problem to solve
My CardDAV provider (fastmail) uses address book groups, rather than categories, adding new entries to groups is costly, time-wise.
💡 idea for improvement
Be able to select Groups or Categories as what to show in the side-bar and I could drag-drop entries to the group.
Ability to select which address book group(s) a contact belongs to on the edit contact page.