curl --request GET \
  --url https://gateway.polymarket.us/v1/subjects

{
  "subjects": [
    {
      "id": 123,
      "name": "<string>",
      "displayName": "<string>",
      "description": "<string>",
      "subjectType": "<string>",
      "image": "<string>",
      "color": "<string>",
      "darkColor": "<string>",
      "createdAt": "<string>",
      "updatedAt": "<string>"
    }
  ]
}