add creator and creation date for terms

[wdduncan]

You may want to consider adding annotations to the terms for the creator and the creation date. For example, class foo might have the annotations:

dcterms:creator <orcid>
dcterms:date <yyyy-mm-dd>

How to specify the creator can turn into a bit of rabbit hole. Do you use an ORCID? Do you use a name? Do you use a combination of ORCID and name? etc. Also, folks who add content later should be contributors (e.g., dcterms:contributor).