Update README.md

Author: henninghall

README.md

@@ -1,3 +1,20 @@
 # react-native-date-picker
 
-A cross platform date picker component for React Native. This component uses the default DatePickerIOS on iOS and a custom picker on Android which has similar look and feel. 
+A cross platform date picker component for React Native. This component uses the default DatePickerIOS on iOS and a custom picker on Android which has similar look and feel. 
+
+## Installation
+
+`$ yarn add @henninghall/react-native-date-picker`
+
+## Usage
+
+```js
+import Picker from '@henninghall/react-native-date-picker';
+
+<Picker
+  date={new Date()}
+  onDateChange={(date) => console.log(date)}
+  style={{ width: 300, height: 210 }}
+/>
+
+```