updating readme#usage

Author: hzitoun

README.md

@@ -3,11 +3,11 @@ Take pictures secretly (without preview or launching device's camera app) from a
 
 ## Usage
 
-- Create a new instance of ```PictureCapturingService ```
-- Implement PictureCapturingListener and override the following methods:
+- Implement the interface ```PictureCapturingListener``` and override the following methods:
     -  ``` void onDoneCapturingAllPhotos(TreeMap<String, byte[]> picturesTaken) ``` which is called when we've done taking pictures from ALL available cameras OR when NO camera was detected on the device;
     -  ``` void onDoneCapturingAllPhotos(TreeMap<String, byte[]> picturesTaken) ``` to get a couple (picture Url, picture Data). Use this method if you don't want to wait for ALL pictures to be ready;
-- Call ```PictureCapturingService#startCapturing(final PictureCapturingListener listener) ``` and pass the listener you just implemented
+- Create a new instance of ```APictureCapturingService```
+- Start capture by calling the method ```APictureCapturingService#startCapturing(PictureCapturingListener listener) ``` and pass the listener you've just implemented
 
 ## How can I support this project?
 - Star this GitHub repo :star: