update readme

Author: rudyhuynh

README.md

@@ -2,4 +2,30 @@
 
 A circular progress chart using react-native-svg
 
-![sample <>](https://github.com/stssoftware/react-native-svg-circular-progress/blob/master/Sample.png "Sample")
+![sample <>](https://github.com/stssoftware/react-native-svg-circular-progress/blob/master/Sample.png "Sample")
+
+## Installation
+````
+npm install react-native-svg react-native-svg-circular-progress --save
+````
+
+## Usage
+````
+import {CircularProgress} from 'react-native-svg-circular-progress'
+
+const App = () => {
+	const percentage = 40
+	return <View>
+		<CircularProgress percentage={percentage}>
+            <View>
+                <Text>{percentage}%</Text>
+            </View>
+        </CircularProgress>
+	</View>
+}
+````
+
+## Props
+ * percentage (default: 80) 
+ * blankColor (default: "#eaeaea") 
+ * donutColor (default: "#43cdcf")