Consolidate OGS API documentations into one, take the obsolete ones offline

[adamreisnz]

Is your feature request related to a problem? Please describe.
It is extremely hard to develop against the OGS API with the amount of obsolete information and API documentation around. It's hard to figure out which are still relevant, and which have since changed. This is causing developer time to be wasted.

There currently (at least) 4 sets of documentation online:

• https://docs.online-go.com/goban/modules/protocol.html
• https://online-go.com/api/v1/ui/config
• https://apidocs.online-go.com/
• https://ogs.docs.apiary.io/

In addition, there's a lot of information floating around on the OGS support forums.

Describe the solution you'd like
Take the obsolete documentation pages offline, and consolidate everything into a single source of truth.

Describe alternatives you've considered
There aren't any good alternatives, really, I think this just needs to be done.