List templates

curl --request GET \
  --url https://app.vern.so/api/v1/templates \
  --header 'x-api-key: <api-key>'

{
  "templates": [
    {
      "slug": "<string>",
      "name": "<string>",
      "description": "<string>",
      "columns": [
        {
          "name": "<string>",
          "description": "<string>",
          "required": true,
          "unique": true,
          "strictRule": "<string>",
          "linkRule": [
            {
              "templateId": "<string>",
              "columnName": "<string>"
            }
          ]
        }
      ]
    }
  ]
}