Global Index references should be non-public

[diffbot-dan-urman]

Per Kris, we have some legacy customers who use the Search API against the Global Index so we do need to provide internal/subscriber-facing documentation on this. However, it's a deprecated workflow that we don't sell on anymore (I gather KG is the preferred way to handle these use cases) and we should not make the documentation public.

Based on #8 there were three FAQ-style articles about the Global Index; it looks like they've all been combined into one page. We should keep an eye out for other references but it looks like we just need to make this one page subscriber-only.

[Swader]

I've been looking into this. TLDR is that if we can make the docs work on the same domain as Diffbot, then our JS should be able to read the login cookie of diffbot.com thereby grabbing the token value. Once we have it we can:

• query it for customer plan
• show / hide certain pages as needed

I am still working on fixing the domain, though. #3