Summary:
Adds a couple test fixtures to validate the interaction of flex gap with children with margins. In both Yoga, and web browsers, these are additive vs collapsing.
Fixes a couple misspellings as well that weren't caught during review.
Changelog:
[Internal]
Reviewed By: lunaleaps
Differential Revision: D41343407
fbshipit-source-id: 427f94faf248901517feff24d334f17ccb85266b
5a257aac85