Croissant vocabulary for crawled datasets

[wumpus]

Related to #738 I would like to create any necessary new controlled language necessary to describe a crawled dataset.

I propose:

• I will write up a single common crawl in croissant
• I'll use existing language, and leave a list of things that apparently needs new language
• An actual croissant expert should go back and forth with me at this point.

I have other interested users -- the ARDC (Alliance for Responsible Data Collection) would like to mandate a machine-readable metadata format for its users. This will serve a role similar to Croissant-RAI.

[benjelloun]

Can some or all of these crawls be thought of as different versions of the same dataset? If so, Croissant has support for representing versions, so you could model them that way. However, there is no mechanism currently available to enumerate all existing versions of a dataset.