Summary:
> Explain the **motivation** for making this change. What existing problem does the pull request solve?
When I'm referring to the `TouchableWithoutFeedback` documentation, I keep noticing this missing 's'.
Closes https://github.com/facebook/react-native/pull/11037
Differential Revision: D4211726
Pulled By: ericvicenti
fbshipit-source-id: 32adf03ec37733128039e064b8fdfa8b817e4a01