Adding marshmallow-code/apispec

[earth2marsh]

also cleaning up some inconsistent capitalization and spacing

[MikeRalphson]

Apart from the repository description, the README and docs for marshmallowcode/api-spec only refer to OAS 2. See also marshmallow-code/apispec#165 - possibly v3 support is WIP?

Also, if we want people to adhere to our branding guidelines, we should pay it back. GitHub styles themselves 'GitHub' not 'github'. I am not prepared to die on this hill, however.

While we're at it, do we want to lose the word necessarily from

These tools are not necessarily endorsed by the OAI.

[earth2marsh]

@MikeRalphson thanks, I'd been told it supported v3, but it looks like that's just partial support today. At what point would we deem it fully supported though?

As for the change, my goal was 1) be consistent, and 2) those GitHub references are strikingly path-like, so I decided to write them as GitHub does in paths. I did not force everything to lower case though because orgs and projects can have caps. When GitHub is used to refer to the service and not the resource, I would always put two caps. :)

I like removing necessarily, will update. I'll also drop apispec for now until either they think they've hit something that qualifies or we have criteria about what "supported" means. Sound good?

[MikeRalphson]

Hard to say, but v2 and v3 should probably at least have parity in the readme.

Thanks for the explanation re: github, makes sense.

Just remembered, we should be getting into the habit of adding a sign-off to our commits as per Jeff-EF.