updating readme instruction

Author: Rishabh

README.md

@@ -1,2 +1,36 @@
 # react-native-rating-element
+
 A simple rating library for react native supporting decimal point and custom icon set
+
+## Installation
+
+Use the package manager npm to install react-native-rating-element.
+
+```bash
+npm install react-native-rating-element
+```
+
+## Usage
+
+```javascript
+import Rating from "react-native-rating-element";
+
+<Rating
+  rated={3.7}
+  totalCount={5}
+  ratingColor="#b5121b"
+  ratingBackgroundColor="#c8c7c8"
+  size={12}
+  icon="ios-star"
+/>
+```
+
+## Contributing
+
+Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.
+
+Please make sure to update tests as appropriate.
+
+## License
+
+[MIT](https://choosealicense.com/licenses/mit/)