TS: add onSwipeableLeftWillDoSomething to defs (#416)
TS: add onSwipeableLeftWillDoSomething to defs (#416)

these methods are documented but missing for TS defs
kmagiera/react-native-gesture-handler,kmagiera/react-native-gesture-handler,kmagiera/react-native-gesture-handler,kmagiera/react-native-gesture-handler,kmagiera/react-native-gesture-handler