curl --request GET \
  --url https://api.elections.kalshi.com/trade-api/v2/milestones

{
  "milestones": [
    {
      "id": "<string>",
      "category": "<string>",
      "type": "<string>",
      "start_date": "2023-11-07T05:31:56Z",
      "related_event_tickers": [
        "<string>"
      ],
      "title": "<string>",
      "notification_message": "<string>",
      "details": {},
      "primary_event_tickers": [
        "<string>"
      ],
      "last_updated_ts": "2023-11-07T05:31:56Z",
      "end_date": "2023-11-07T05:31:56Z",
      "source_id": "<string>"
    }
  ],
  "cursor": "<string>"
}