Add docker badges to README

Author: ferrarimarco

README.md

@@ -1,5 +1,11 @@
 # Dockerized Github Changelog Generator
 
+
+![Docker Stars](https://img.shields.io/docker/stars/ferrarimarco/github-changelog-generator.svg)
+[![Docker Pulls](https://img.shields.io/docker/pulls/ferrarimarco/github-changelog-generator.svg)](https://hub.docker.com/r/ferrarimarco/github-changelog-generator/)
+[![Docker Automated build](https://img.shields.io/docker/automated/ferrarimarco/github-changelog-generator.svg)](https://hub.docker.com/r/ferrarimarco/github-changelog-generator/)
+![Docker Build Status](https://img.shields.io/docker/build/ferrarimarco/github-changelog-generator.svg)
+
 This is a semi-official containerization of [Github Changelog Generator](https://github.com/skywinder/github-changelog-generator).
 
 For each Github Changelog Generator release, you will find the corresponding docker image tag.