doc: Add version badge to README

Author: Nick Ardecky

README.md

@@ -1,5 +1,6 @@
 # zingchart-react
 
+![](https://img.shields.io/npm/v/zingchart-react)
 ![](https://github.com/zingchart/zingchart-react/workflows/Build/badge.svg?branch=master)
 ![](https://github.com/zingchart/zingchart-react/workflows/Test/badge.svg?branch=master)
 ![](https://img.shields.io/npm/dw/zingchart-react)