Added npm badge button

README.md

 
+[![npm version](https://badge.fury.io/js/de.appplant.cordova.plugin.local-notification.svg)](http://badge.fury.io/js/de.appplant.cordova.plugin.local-notification)
 [![PayPayl donate button](https://img.shields.io/badge/paypal-donate-yellow.svg)](https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=L3HKQCD9UA35A "Donate once-off to this project using Paypal")
 
 #### :bangbang: Please vote for these cordova-windows issues :bangbang: