Decompose what is in the Wiki to services.greenbuttondata.org

[MartyBurns]

The services.greenbuttondata.org web presence has support for API testing as well as technical documentation in support of developers. Move relevant content from https://github.com/energyos/OpenESPI-wiki to incorporate into this site. Deprecate the use of the OpenESPI-wiki project.

[jateeter]

There are two parts to this energyos/OpenESPI-GreenButton-API-Documentation repository:

1 - the developer page(s) that are located at the root level.
2 - the Restful API (swagger) pages that are located under the /API folder

This issue covers both, but it may be that the two parts listed above will reside in different places when the dust settles.

(note that neither of these items are currently in the wiki ref: the name of this issue)