canari further_info_url

[bnlawrence]

We could just use a github wiki, or a github jekyll site, or stand something up at CEDA.  Whatever we do needs to support errata and probably our own "ad-hoc" es-doc. Probably wants a zenodo DOI.

[bnlawrence]

Also should support full documentation of our initialisation index nomenclature.

[bnlawrence]

We’ll use GitHub, maybe with a domain name. Which could point to CEDA or a wiki. CMS decision.