[PR] Update README.md
[PR] Update README.md

Summary:
Make README consistent with examples on Flow's website
Pull Request resolved: https://github.com/facebook/flow/pull/7098

Reviewed By: jbrown215

Differential Revision: D13574415

Pulled By: nmote

fbshipit-source-id: dc8be18836bafdf13676350c4467316d35d42925

mroch/flow,popham/flow,AgentME/flow,samwgoldman/flow,facebook/flow,samwgoldman/flow,mroch/flow,facebook/flow,popham/flow,popham/flow,mroch/flow,samwgoldman/flow,samwgoldman/flow,AgentME/flow,gabelevi/flow,gabelevi/flow,mroch/flow,facebook/flow,AgentME/flow,popham/flow,mroch/flow,popham/flow,facebook/flow,mroch/flow,popham/flow,gabelevi/flow,AgentME/flow,AgentME/flow,mroch/flow,samwgoldman/flow,gabelevi/flow,popham/flow,gabelevi/flow,facebook/flow,facebook/flow,samwgoldman/flow,gabelevi/flow,samwgoldman/flow,gabelevi/flow,facebook/flow