add Docker badge to README

Author: ayobi

README.md

@@ -1,6 +1,7 @@
 # ITSxRust
 [![Bioconda](https://img.shields.io/conda/dn/bioconda/itsxrust.svg?label=Bioconda)](https://bioconda.github.io/recipes/itsxrust/README.html)
 [![Conda Version](https://img.shields.io/conda/vn/bioconda/itsxrust.svg)](https://anaconda.org/bioconda/itsxrust)
+[![Docker](https://img.shields.io/badge/Docker-ghcr.io%2Fayobi%2Fitsxrust-blue?logo=docker)](https://github.com/ayobi/ITSxRust/pkgs/container/itsxrust)
 [![GitHub Release](https://img.shields.io/github/v/release/ayobi/ITSxRust)](https://github.com/ayobi/ITSxRust/releases)
 [![CI](https://github.com/ayobi/ITSxRust/actions/workflows/ci.yml/badge.svg)](https://github.com/ayobi/ITSxRust/actions)
 [![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](LICENSE)