Summary:
* Copy-pasting into a terminal _can_ be dangerous. [See this](https://thejh.net/misc/website-terminal-copy-paste). Thus I've changed "paste" to "type". People are probably going to do this anyway but there is not need to suggest copy-pasting `sudo`commands.
* `sudo` is not required to do a global npm install (of course you can do it). Thus I've removed the "sudo" for the flow install command. This is consistent with the general getting started page where `sudo` isn't used in front of `npm install -g` either.
Closes https://github.com/facebook/react-native/pull/7330
Differential Revision: D3252286
fb-gh-sync-id: 7d4580b6bf828e4a833e02365045f3bb9276cfef
fbshipit-source-id: 7d4580b6bf828e4a833e02365045f3bb9276cfef
Summary:1. add information about automake and python-dev apt dependencies
2. Suggest current watchman version (4.5 vs 4.1)
Closes https://github.com/facebook/react-native/pull/6784
Differential Revision: D3161652
fb-gh-sync-id: 2a13b315fcb6f1898a5b3be12ddf15ed457befdb
fbshipit-source-id: 2a13b315fcb6f1898a5b3be12ddf15ed457befdb
Summary:Remove Trailing Spaces.
Why:
Sometimes there are conflicts with trailing spaces
Saves space
Those whose tools automatically delete them will have their pr watered down with trailing space removal
Closes https://github.com/facebook/react-native/pull/6787
Differential Revision: D3144704
fb-gh-sync-id: d8a62f115a3f8a8a49d5b07f56c540a02af38cf8
fbshipit-source-id: d8a62f115a3f8a8a49d5b07f56c540a02af38cf8
