provide schema, refactor for version 2

[tacman]

{
  "Title": "Ferdinandsbrücke Project, Vienna, Austria (Elevation, preliminary version)",
  "Artist": [
    "Otto Wagner"
  ],
  "ConstituentID": [
    6210
  ],
  "ArtistBio": [
    "Austrian, 1841–1918"
  ],
  "Nationality": [
    "Austrian"
  ],
  "BeginDate": [
    1841
  ],
  "EndDate": [
    1918
  ],
  "Gender": [
    "male"
  ],
  "Date": "1896",
  "Medium": "Ink and cut-and-pasted painted pages on paper",
  "Dimensions": "19 1/8 x 66 1/2\" (48.6 x 168.9 cm)",
  "CreditLine": "Fractional and promised gift of Jo Carole and Ronald S. Lauder",
  "AccessionNumber": "885.1996",
  "Classification": "Architecture",
  "Department": "Architecture & Design",
  "DateAcquired": "1996-04-09",
  "Cataloged": "Y",
  "ObjectID": 2,
  "URL": "https://www.moma.org/collection/works/2",
  "ImageURL": "https://www.moma.org/media/W1siZiIsIjUyNzc3MCJdLFsicCIsImNvbnZlcnQiLCItcmVzaXplIDEwMjR4MTAyNFx1MDAzZSJdXQ.jpg?sha=712ac0fd74ea5bd5",
  "OnView": "",
  "Height (cm)": 48.6,
  "Width (cm)": 168.9
}

It'd be great if all these fields were documented.

In the process, I think it might evoke a conversation about the structure, like why is there a "Gender" field on an artwork? And "BeginDate" and "EndDate" on an artwork sounds like when the artwork was created, not the birth/death dates of the artist. If BeginData were moved to inside the artist then it could also be called birthYear and be an integer rather than an array.

Tiny issues. I know how hard it is to manage the schema for this kind of data, and I appreciate it very much that it is even available as is! Thanks for making it available!