Trivial: Fix typo in README link (#23792)
Trivial: Fix typo in README link (#23792)

Summary:
Link to docs repo is broken in markdown.
Pull Request resolved: https://github.com/facebook/react-native/pull/23792

Differential Revision: D14348403

Pulled By: hramos

fbshipit-source-id: 76cfd620ec87250df77e535b3c215d682b19c8f7

janicduplessis/react-native,pandiaraj44/react-native,janicduplessis/react-native,exponentjs/react-native,janicduplessis/react-native,exponent/react-native,janicduplessis/react-native,pandiaraj44/react-native,javache/react-native,exponentjs/react-native,exponent/react-native,exponent/react-native,facebook/react-native,hoangpham95/react-native,myntra/react-native,facebook/react-native,hoangpham95/react-native,exponentjs/react-native,arthuralee/react-native,hammerandchisel/react-native,facebook/react-native,exponentjs/react-native,exponent/react-native,javache/react-native,facebook/react-native,hoangpham95/react-native,hammerandchisel/react-native,janicduplessis/react-native,myntra/react-native,myntra/react-native,hammerandchisel/react-native,myntra/react-native,pandiaraj44/react-native,exponent/react-native,myntra/react-native,arthuralee/react-native,pandiaraj44/react-native,facebook/react-native,javache/react-native,exponent/react-native,myntra/react-native,hoangpham95/react-native,janicduplessis/react-native,janicduplessis/react-native,javache/react-native,exponentjs/react-native,exponentjs/react-native,facebook/react-native,javache/react-native,hoangpham95/react-native,pandiaraj44/react-native,hoangpham95/react-native,facebook/react-native,exponentjs/react-native,myntra/react-native,hammerandchisel/react-native,pandiaraj44/react-native,hoangpham95/react-native,javache/react-native,myntra/react-native,pandiaraj44/react-native,arthuralee/react-native,arthuralee/react-native,exponent/react-native,hammerandchisel/react-native,javache/react-native,hoangpham95/react-native,myntra/react-native,exponent/react-native,hammerandchisel/react-native,hammerandchisel/react-native,arthuralee/react-native,hammerandchisel/react-native,facebook/react-native,pandiaraj44/react-native,facebook/react-native,javache/react-native,exponentjs/react-native,janicduplessis/react-native,javache/react-native