Fix #96 by making each docset its own Helm source.

[kidd]

Thanks for your contribution!

I've just learned that with left and right (and c-o) you can navigate through different sources so this is definately much more than a cosmetic change :).

[xiongtx]

That's not all you can do.

Within a particular source, C-M-a calls helm-show-all-in-this-source-only, which, as the name suggests, shows only candidates from a single source. Thus, you can search within a single docset. I find this useful when working on web development, because I often have several docsets (Meteor, Bootstrap, etc.) active at the same time.

You can show all sources again with C-M-e, bound to helm-display-all-sources.

[kidd]

cool!

[areina]

Hey @xiongtx , thank you so much, this is really helpful.