Get a user group

curl --request GET \
  --url https://core.api.ravennahq.com/api/user-groups/{id} \
  --header 'x-ravenna-api-token: <api-key>'

{
  "id": "<string>",
  "name": "<string>",
  "description": "<string>",
  "emoji": "<string>",
  "icon": "<string>",
  "color": "<string>",
  "organizationId": "<string>",
  "_count": {
    "users": 123
  },
  "createdAt": "<string>",
  "updatedAt": "<string>"
}