Schema.org mappings

See https://schema.org/Dataset and https://developers.google.com/search/docs/data-types/dataset

Some properties in netCDF and thus BALD may be captured from ACDD and CFTerms/Standard name. An authoritative ACDD vocabulary is being developed (see here in the meantime http://cor.esipfed.org/ont/~jyu/test-acdd)

schema.org	required?	BALD predicate
description	required	acdd:summary
name	required	acdd:title or nug:title
citation	recommended
identifier	recommended	acdd:id
keywords	recommended	acdd:keywords
license	recommended	acdd:license
sameAs	recommended
spatialCoverage	recommended	acdd:geospatial_*
temporalCoverage	recommended	acdd:time_coverage*
variableMeasured	recommended	cf:standard_name
version	recommended	acdd:product_version ?
url	recommended