update README and dependencies

Author: DaniAkash

README.md

@@ -20,12 +20,12 @@ import { responsiveHeight, responsiveWidth, responsiveFontSize } from 'react-nat
 const styles = StyleSheet.create({
   container: {
     justifyContent: 'center',
-    height: responsiveHeight(50),
-    width: responsiveWidth(50),
+    height: responsiveHeight(50), // 50% of screen height
+    width: responsiveWidth(50), // 50% of screen width
     alignItems: 'center',
   },
   sampleText: {
-    fontSize: responsiveFontSize(2),
+    fontSize: responsiveFontSize(2), // 2% of total screen size
   }
 });
 ```

package.json

@@ -20,6 +20,6 @@
   "repository": "DaniAkash/react-native-responsive-dimensions",
   "license": "MIT",
   "dependencies": {
-    "react-native": "^0.42.0"
+    "react-native": "x"
   }
 }