doc(CHANGELOG): add 2.1.1 release notes
doc(CHANGELOG): add 2.1.1 release notes

archriss/react-native-snap-carousel,houseofstylist/react-native-snap-carousel,archriss/react-native-snap-carousel,houseofstylist/react-native-snap-carousel,archriss/react-native-snap-carousel,houseofstylist/react-native-snap-carousel,archriss/react-native-snap-carousel