Added Docker automated build hook and readme badges for Docker

- Build arguments are injected by the build hook
- Badges added: number of pulls, stars and if the build is automated

README.md

@@ -50,6 +50,10 @@ go get github.com/jesseduffield/lazydocker
 
 ### Docker
 
+[![Docker Pulls](https://img.shields.io/docker/pulls/jesseduffield/lazydocker.svg)](https://hub.docker.com/r/jesseduffield/lazydocker)
+[![Docker Stars](https://img.shields.io/docker/stars/jesseduffield/lazydocker.svg)](https://hub.docker.com/r/jesseduffield/lazydocker)
+[![Docker Automated](https://img.shields.io/docker/cloud/automated/jesseduffield/lazydocker.svg)](https://hub.docker.com/r/jesseduffield/lazydocker)
+
 1. <details><summary>Build it...</summary><p>
 
     - If you have a x86_64 CPU architecture

hooks/build

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+docker build --build-arg BUILD_DATE=`date -u +"%Y-%m-%dT%H:%M:%SZ"` \
+             --build-arg VCS_REF=`git rev-parse --short HEAD` \
+             --build-arg VERSION=`git describe --abbrev=0 --tag` \
+             -t $IMAGE_NAME .