add docker badge

README.md

@@ -2,7 +2,8 @@
 [![build status](https://github.com/AnderEnder/s3find-rs/workflows/Rust/badge.svg)](https://github.com/AnderEnder/s3find-rs/actions)
 [![freebsd build status](https://api.cirrus-ci.com/github/AnderEnder/s3find-rs.svg)](https://cirrus-ci.com/github/AnderEnder/s3find-rs/>)
 [![codecov](https://codecov.io/gh/AnderEnder/s3find-rs/branch/master/graph/badge.svg)](https://codecov.io/gh/AnderEnder/s3find-rs)
-[![Crates.io](https://img.shields.io/crates/v/s3find.svg)](https://crates.io/crates/s3find)
+[![crates.io](https://img.shields.io/crates/v/s3find.svg)](https://crates.io/crates/s3find)
+[![docker image](https://img.shields.io/docker/automated/anderender/s3find.svg)](https://hub.docker.com/r/anderender/s3find)
 
 
 A command line utility to walk an Amazon S3 hierarchy. An analog of find for Amazon S3.