Summary:
Renamed `eslint-config-react-native` to `eslint-config-react-native-community`, due to the fact, that initial name is already taken on `npm`. Additionally, I added very simple `README.md` file, to prepare the package to be published.

[General] [Changed] - Changed `eslint-config-react-native` name to `eslint-config-react-native-community`
Pull Request resolved: https://github.com/facebook/react-native/pull/23718

Differential Revision: D14298553

Pulled By: cpojer

fbshipit-source-id: bad5a42502ccdebf5f95d8217187be23bbf8f26c