Retrieves a severity

curl --request GET \
  --url https://api.rootly.com/v1/severities/{id} \
  --header 'Authorization: Bearer <token>'

{
  "data": {
    "id": "bb759ff5-50ad-403d-a6bb-c377774223b8",
    "type": "severities",
    "attributes": {
      "name": "nj1f8",
      "slug": "nj1f8",
      "description": "Quaerat sint error similique.",
      "severity": "medium",
      "color": "#E58A1F",
      "position": 1,
      "notify_emails": [],
      "slack_channels": [],
      "slack_aliases": [],
      "created_at": "2025-09-18T20:59:14.165-07:00",
      "updated_at": "2025-09-18T20:59:14.165-07:00"
    }
  }
}