[skip ci] Add badge and improved formatting of README

Author: cybertk

README.md

@@ -3,6 +3,7 @@
 > MagicVision nodejs development env based on Docker
 
 [![Build Status](https://travis-ci.org/GetMagicVision/docker-nodejs-dev.svg)](https://travis-ci.org/GetMagicVision/docker-nodejs-dev)
+[![Docker Hub](https://img.shields.io/badge/docker-ready-blue.svg)](https://registry.hub.docker.com/u/magicvision/nodejs-dev/)
 [![Docker image layers and size](https://badge.imagelayers.io/magicvision/nodejs-dev:latest.svg)](https://imagelayers.io/?images=magicvision/nodejs-dev:latest 'Get your own badge on imagelayers.io')
 
 ## Features