Add information about the container image

Author: moutonjeremy

README.md

@@ -5,6 +5,7 @@ github-actions-exporter for prometheus
 ![Docker Pulls](https://img.shields.io/docker/pulls/spendeskplatform/github-actions-exporter)
 [![Go Report Card](https://goreportcard.com/badge/github.com/Spendesk/github-actions-exporter)](https://goreportcard.com/report/github.com/Spendesk/github-actions-exporter)
 
+Container image : https://hub.docker.com/repository/docker/spendeskplatform/github-actions-exporter
 
 ## Information
 If you want to monitor a public repository, you must put the public_repo option in the repo scope of your github token.