Update README.md

README.md

@@ -13,6 +13,7 @@ crowi-plus [![Chat on Slack](https://crowi-plus-slackin.weseek.co.jp/badge.svg)]
 [![wercker status](https://app.wercker.com/status/39cdc49d067d65c39cb35d52ceae6dc1/s/master "wercker status")](https://app.wercker.com/project/byKey/39cdc49d067d65c39cb35d52ceae6dc1)
 [![dependencies status](https://david-dm.org/weseek/crowi-plus.svg)](https://david-dm.org/weseek/crowi-plus)
 [![devDependencies Status](https://david-dm.org/weseek/crowi-plus/dev-status.svg)](https://david-dm.org/weseek/crowi-plus?type=dev)
+[![docker pulls](https://img.shields.io/docker/pulls/weseek/crowi-plus.svg)](https://hub.docker.com/r/weseek/crowi-plus/)
 [![MIT License](http://img.shields.io/badge/license-MIT-blue.svg?style=flat)](LICENSE)