[docs] document implicit-inexact-object
[docs] document implicit-inexact-object

Summary: Adds documentation for the implicit-inexact-object lint. Now that the PRs to flow-typed have landed, it should be safe for people to use.

Reviewed By: panagosg7

Differential Revision: D16963097

fbshipit-source-id: b79d7dbffd8df960f9201358a8a3cca3628ae0c3

mroch/flow,samwgoldman/flow,facebook/flow,gabelevi/flow,facebook/flow,gabelevi/flow,facebook/flow,facebook/flow,gabelevi/flow,facebook/flow,samwgoldman/flow,gabelevi/flow,facebook/flow,mroch/flow,mroch/flow,mroch/flow,facebook/flow,samwgoldman/flow,mroch/flow,mroch/flow,gabelevi/flow,samwgoldman/flow,mroch/flow,gabelevi/flow,samwgoldman/flow,samwgoldman/flow,samwgoldman/flow,gabelevi/flow