Improved the clarity of the top-level API doc (#2984)
Improved the clarity of the top-level API doc (#2984)

I clarified some of the language here so that it is easier for the beginner to understand. (It was a little bit awkward before)
ceyhuno/react-native-navigation,3sidedcube/react-native-navigation,chicojasl/react-native-navigation,3sidedcube/react-native-navigation,Jpoliachik/react-native-navigation,guyca/react-native-navigation,ceyhuno/react-native-navigation,Jpoliachik/react-native-navigation,wix/react-native-navigation,thanhzusu/react-native-navigation,chicojasl/react-native-navigation,wix/react-native-navigation,thanhzusu/react-native-navigation,Jpoliachik/react-native-navigation,thanhzusu/react-native-navigation,3sidedcube/react-native-navigation,thanhzusu/react-native-navigation,ceyhuno/react-native-navigation,guyca/react-native-navigation,chicojasl/react-native-navigation,Jpoliachik/react-native-navigation,chicojasl/react-native-navigation,wix/react-native-navigation,ceyhuno/react-native-navigation,Jpoliachik/react-native-navigation,wix/react-native-navigation,thanhzusu/react-native-navigation,chicojasl/react-native-navigation,guyca/react-native-navigation,ceyhuno/react-native-navigation,wix/react-native-navigation,Jpoliachik/react-native-navigation,guyca/react-native-navigation,3sidedcube/react-native-navigation,wix/react-native-navigation,thanhzusu/react-native-navigation,ceyhuno/react-native-navigation,chicojasl/react-native-navigation