Validation artefacts

[michmech]

(Submitted by Miloš Jakubíček)

It has been brought to my attention that one of the remaining outstanding issues is that we still need to take a decision on validation artifacts, so this is a formal request to do so.

[jmccrae]

I have already written a validator... but DTD/XSD and JSON Schema and RDF shapes would all be very useful.

[jmccrae]

RDF shapes were implemented and merged in #108

[DavidFatDavidF]

@jmccrae @mjakubicek @vojtech-kovar and others working on validation artifacts.
Apart from the artifacts that you should provide via the ../schemas/ folder you should also list, describe, and reference them from Appendix C

<appendix role="informative" id="Validation">
    <title>Machine Readable Validation Artifacts</title>

All normative artifacts also have to be listed in the front matter under

<legalnotice role="additional">
      <title>Additional artifacts</title>

[jmccrae]

@DavidFatDavidF could you create the folder in the repo?