Summary:
## Changes in this pull request
Initial suggested implementation for https://github.com/Instagram/IGListKit/issues/1387.
### Checklist
- [x] All tests pass. Demo project builds and runs.
- [x] I added tests, an experiment, or detailed why my change isn't tested.
- [x] I added an entry to the `CHANGELOG.md` for any breaking changes, enhancements, or bug fixes.
- [x] I have reviewed the [contributing guide](https://github.com/Instagram/IGListKit/blob/master/.github/CONTRIBUTING.md)
Pull Request resolved: https://github.com/Instagram/IGListKit/pull/1388
Reviewed By: lorixx
Differential Revision: D18687735
Pulled By: natestedman
fbshipit-source-id: f9cc70ced3f788771fd3f0443b56befbedb04166