Create a user group

curl --request POST \
  --url https://core.api.ravennahq.com/api/user-groups \
  --header 'Content-Type: application/json' \
  --header 'x-ravenna-api-token: <api-key>' \
  --data '{
  "name": "<string>",
  "description": "<string>",
  "emoji": "<string>",
  "icon": "<string>",
  "color": "<string>",
  "userIds": [
    "<string>"
  ],
  "workspaceIds": [
    "<string>"
  ]
}'

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