Fix typos in README
Fix typos in README

Fix #338

joelbyler/flight,icecreamliker/flight,Shinchy/flight,KyawNaingTun/flight,david84/flight,joelbyler/flight,KyawNaingTun/flight,robertknight/flight,david84/flight,icecreamliker/flight,robertknight/flight,Shinchy/flight