Add npm-version Badge

Author: okaufmann

README.md

@@ -3,6 +3,8 @@ elixir-typescript
 
 **(forked from laravel-elixir-typescript by [MikeyAlder](https://github.com/MikeyAlder/laravel-elixir-typescript))**
 
+[![npm version](https://badge.fury.io/js/elixir-typescript.svg)](https://badge.fury.io/js/elixir-typescript)
+
 ## Prerequirement
 You have to install [Laravel's Elixir](http://laravel.com/docs/master/elixir)(Version 3.0 or higher) and its dependencies first.