prettier

diff

• docs(README): use yarn add for consistency (#734)
• Make trailing-comma option support 2 different modes (#641)
• Update README with valid trailingComma options
• Fix await ternary parenthesis (#740)
• Fix missing dangling comment in exports (#741)
• Fix missing dangling comments in arrays (#744)
• Remove extra parenthesis around await inside of unary expression (#745)
• Fix missing dangling comments in for loop (#742)
• Add note about trailingComma option in versions 0.18.0 and below
• Add missing explanatory comment in ForStatement case (#748)
• Fix leading & operators in flow types ()