missing artifact standards

[timm]

[drpaulralph]

Draft artifacts standards can be found here: https://github.com/researchart/patterns/blob/master/standards/artifact.md

Still needs work before incorporating.

[drpaulralph]

@davisjam that's a link to a different github repo. When the artifact standard is moved to this repo, it will be in docs or Supplements depending on its content.