Design guidelines and framework overview about reactivecocoa

[jspahrsummers]

If an edge case isn't documented, it's probably not intended behavior; for example, #136 and #138 are both critical bugs that need to be fixed.

I agree that RAC could use some better documentation, but, unless we're talking about examples/tutorials, I'm not sure why it needs to be external to class and method documentation – maybe with the one exception of memory management (since it's sort of a global philosophy).

[dannygreg]

"Edge cases" aside, I definitely think RAC is in need of a nice overview document. A place to explain overarching concepts of the framework and where the various classes fit in. A primer before diving into the class-based documentation.

Only having class-level documentation can be fairly disorientating when discovering a new framework.

[joshaber]

Yep, I agree an overview doc would be good. Some things don't fit naturally as documentation on one class.

[jspahrsummers]

(Edited issue title to match the discussion.)