Add links to Docker image

README.md

@@ -1,4 +1,4 @@
-# Prometheus SQL Exporter [![Build Status](https://travis-ci.org/free/sql_exporter.svg)](https://travis-ci.org/free/sql_exporter) [![Go Report Card](https://goreportcard.com/badge/github.com/free/sql_exporter)](https://goreportcard.com/report/github.com/free/sql_exporter) [![GoDoc](https://godoc.org/github.com/free/sql_exporter?status.svg)](https://godoc.org/github.com/free/sql_exporter)
+# Prometheus SQL Exporter [![Build Status](https://travis-ci.org/free/sql_exporter.svg)](https://travis-ci.org/free/sql_exporter) [![Go Report Card](https://goreportcard.com/badge/github.com/free/sql_exporter)](https://goreportcard.com/report/github.com/free/sql_exporter) [![GoDoc](https://godoc.org/github.com/free/sql_exporter?status.svg)](https://godoc.org/github.com/free/sql_exporter) [![Docker Pulls](https://img.shields.io/docker/pulls/githubfree/sql_exporter.svg?maxAge=604800)](https://hub.docker.com/r/githubfree/sql_exporter)
 
 Database agnostic SQL exporter for [Prometheus](https://prometheus.io).
 
@@ -20,7 +20,7 @@ metrics when queried more frequently than the configured interval.
 
 ## Usage
 
-Get Prometheus SQL Exporter, either as a [packaged release](https://github.com/free/sql_exporter/releases/latest) or
+Get Prometheus SQL Exporter, either as a [packaged release](https://github.com/free/sql_exporter/releases/latest), as a [Docker image](https://hub.docker.com/r/githubfree/sql_exporter) or
 build it yourself:
 
 ```