Inspector: Add docs for collections

[josephjclark]

The adaptor-docs panel at the moment only shows documentation for the current adaptor (ie, common or http or whatever)

But soon Collections and the Collections API will be available to all adaptors.

We need to work out a way to load the collections API into the list.

[josephjclark]

I suddenly wonder if there's a different concern here.

Rather than documenting collections as its own adaptor, as we do now, should we just append the collections API to every other adaptor?

A bit like how we handle common in other adaptors:

[christad92]

@josephjclark is this still on your radar?

[josephjclark]

I suppose so but I have no plans do it any time soon. Doesn't have to be me who does it ;)

[stuartc]

This one feels straight forward, but two aspects make give me pause:

1. Knowing which version of the collections adaptor to pull the docs for? I'm not sure that is easily accessible in Lightning right now.
2. Pull and merging the docs, is that going to be tricky?