Create a new user group

{
  "name": "Patrons",
  "description": "My subscribers",
  "add_members": [
    "username / email / fediverse address"
  ],
  "remove_members": [
    "username / email / fediverse address"
  ]
}

{
  "@id": "https://example.com/creators/abc123/groups/1",
  "@type": "Group",
  "members": [
    "username"
  ],
  "name": "Patrons",
  "description": "My subscribers"
}