Format metadata in a tagged data format (e.g., JSON-LD)

[huddlej]

Proposed feature

Consider using JSON-LD for data type annotations and linking, as this also enables semantic tagging for fields which is what can enable further automatic processing of metadata beyond just “how is this date formatted”. The format we should doesn’t have to be JSON-LD per se; any tagged data format in the same vein could do, and there are variants for CSV/TSV, etc.

Related issues

Adding support for more sophisticated metadata as in #607 and #609.