Add badges to readme
Badges are fun, let's use Shields.io. Should look something like this for docker:
Docker Stars: https://img.shields.io/docker/stars/gableroux/unity3d.svg
Docker Pulls: https://img.shields.io/docker/pulls/gableroux/unity3d.svg
Docker Automated build https://img.shields.io/docker/automated/gableroux/unity3d.svg
Docker Build Status https://img.shields.io/docker/build/gableroux/unity3d.svg
Markdown to add
[![Docker Stars](https://img.shields.io/docker/stars/gableroux/unity3d.svg)](https://hub.docker.com/r/gableroux/unity3d/)
[![Docker Pulls](https://img.shields.io/docker/pulls/gableroux/unity3d.svg)](https://hub.docker.com/r/gableroux/unity3d/)
[![Docker Automated buil](https://img.shields.io/docker/automated/gableroux/unity3d.svg)](https://hub.docker.com/r/gableroux/unity3d/)
[![Docker Build Statu](https://img.shields.io/docker/build/gableroux/unity3d.svg)](https://hub.docker.com/r/gableroux/unity3d/)
Result:
Edited by Gabriel Le Breton