Specify metadata of JSON-LD artefacts

[minhnh]

JSON-LD models and metamodels now doesn't include metadata like version or concept descriptions. Such info should also be included, so that automated generation of documentation is possible.

Metadata can be added, for example, using rdf:Description and/or rdfs:Resource. Parsing needs to be tested with rdflib to see what would work.

[argenos]

Some relevant json-ld concepts to look into: @vocab, @version (though it seems to be just about the json-ld spec version), and @base, see https://www.w3.org/TR/json-ld/#json-ld-1-1-processing-mode

[argenos]

See also dcterms:description as used in the qudt schema: https://qudt.org/vocab/unit/M.html

The versions also seem to be mostly part of the IRI. See also rdfs:isDefinedBy

The @base keyword might be useful here, see the qudt meta model: https://github.com/comp-rob2b/metamodels/blob/main/qudt.json