Summary:Fix bad wording in the docs change I did in #6534
cc mkonicek
Closes https://github.com/facebook/react-native/pull/6598
Differential Revision: D3085957
Pulled By: vjeux
fb-gh-sync-id: 2b45ac72acf089be6cf8e815aac430a2ce9d08ed
shipit-source-id: 2b45ac72acf089be6cf8e815aac430a2ce9d08ed