added paypal

README.md

@@ -2,6 +2,7 @@ UsbSerial [![Build Status](https://travis-ci.org/felHR85/UsbSerial.svg?branch=ma
 =========
 Usb serial controller for Android. For more information, there is [a more complete description](http://felhr85.net/2014/11/11/usbserial-a-serial-port-driver-library-for-android-v2-0/).
 
+[If UsbSerial helped you with your projects please consider donating a little sum :)](https://www.paypal.me/felhr)
 [A brief list of Apps and projects using UsbSerial](http://felhr85.net/2016/03/19/apps-and-projects-using-usbserial/)
 
 Devices Supported