Summary:
Created a new demo that shows off how to:
- Inject dependencies to section controllers
- Objects shared between section controllers
- Things that aren't the core "object"
- Announce changes from the VC that make their way to the section controllers
- Without calling updates
Closes https://github.com/Instagram/IGListKit/pull/612
Differential Revision: D4827188
Pulled By: rnystrom
fbshipit-source-id: 9575df0e105fd06f9a59db49432b19e8b824e0e3
