Summary:
Solves #203
- [x] Sample Objc and Swift apps now have default configs(i.e non-recursive header search paths)
- [x] Fix for the cocoapods default config by adding FBMacros.h file in `Core` subspec
- [x] Updated the Spec(0.6.15) so that 0.6.15 works for default configs
- [x] Updated the doc
Pull Request resolved: https://github.com/facebook/flipper/pull/205
Reviewed By: passy
Differential Revision: D9148358
Pulled By: priteshrnandgaonkar
fbshipit-source-id: e6d32d9cde7b100573bd9a9996f0ec850b269d28