List sections

curl --request GET \
  --url https://mkk.celebi.me/api/sections

{
  "sections": [
    {
      "id": "<string>",
      "sectionId": "<string>",
      "name": "<string>",
      "sort_order": 123,
      "line_item_count": 123,
      "document_count": 123,
      "fund_count": 123
    }
  ]
}