Dcat alignments schema

[dr-shorthair]

Tabulation of the provisional DCAT-schema.org mapping, for potential feedback through 2PWD.
See preview at https://rawgit.com/w3c/dxwg/dcat-alignments-schema/dcat/index.html#alignments

In response to #251

[agbeltran]

W.r.t Google Dataset Search, we should also point to https://developers.google.com/search/docs/data-types/dataset where it indicates that equivalent DCAT structures to schema.org are also indexed.

[agbeltran]

I'm going to do minor edits on the text based on the acknowledgement at the bottom of https://schema.org/Dataset

"This class is based upon W3C DCAT work, and benefits from collaboration around the DCAT, ADMS and VoID vocabularies. See http://www.w3.org/wiki/WebSchemas/Datasets for full details and mappings."

There was a mapping between sdo, dcat, adms and void at https://www.w3.org/wiki/WebSchemas/Datasets

[dr-shorthair]

@agbeltran Suggest you make them directly on this branch so we can do a single merge.

[larsgsvensson]

Is the mapping provided at https://www.w3.org/wiki/WebSchemas/Datasets really correct? It says that dcat:Dataset is equivalent to void:Dataset. I always thought that dcat:Distribution is equivalent to void:Dataset since a void:Dataset is defined thus: "A dataset is a set of RDF triples that are published, maintained or aggregated by a single provider." dcat:Datasets shouldn't know anything about abstract or concrete syntaxes.

[agbeltran]

We won't be claiming that it is correct, but pointing to it as the mapping that was done to extend schema.org for describing datasets and data catalogs.

[davebrowning]

That last commit - should it say <code>schema</code> rather than <code>code</code>?
Apart from that - all looks fine, so I've made that change