Summary:
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Changing all pages in doc to have title " - React Native", which will make the results easier to distinguish like suggested in issue #15659.
I'm not shure how to write a test to this but if you open any page in doc you can see the page title has changed when the title is passed to Site component.
Closes https://github.com/facebook/react-native/pull/15714
Differential Revision: D5739971
Pulled By: TheSavior
fbshipit-source-id: ba9b5ea83fe5c502653972262eb993a24941a62e
2b86aba390