Added the Test Coverage Badge (#24)

![Screenshot 2023-11-28 at 23 11
31](https://github.com/openhue/openhue-cli/assets/39826516/c508a47f-9832-407c-9c84-6bf2cb870e57)

60%, that's bad, let's improve it ASAP!

README.md

@@ -1,7 +1,9 @@
 # OpenHue CLI
 [![Build](https://github.com/openhue/openhue-cli/actions/workflows/build.yml/badge.svg)](https://github.com/openhue/openhue-cli/actions/workflows/build.yml)
 [![CodeQL](https://github.com/openhue/openhue-cli/actions/workflows/github-code-scanning/codeql/badge.svg)](https://github.com/openhue/openhue-cli/actions/workflows/github-code-scanning/codeql)
-[![Maintainability with Code Climate](https://api.codeclimate.com/v1/badges/fb934bb37c36a04f8efd/maintainability)](https://codeclimate.com/github/openhue/openhue-cli/maintainability)[![Docker Image Size (tag)](https://img.shields.io/docker/image-size/openhue/cli/latest)](https://hub.docker.com/r/openhue/cli)
+[![Maintainability with Code Climate](https://api.codeclimate.com/v1/badges/fb934bb37c36a04f8efd/maintainability)](https://codeclimate.com/github/openhue/openhue-cli/maintainability)
+[![Test Coverage](https://api.codeclimate.com/v1/badges/fb934bb37c36a04f8efd/test_coverage)](https://codeclimate.com/github/openhue/openhue-cli/test_coverage)
+[![Docker Image Size (tag)](https://img.shields.io/docker/image-size/openhue/cli/latest)](https://hub.docker.com/r/openhue/cli)
 [![GitHub Repo stars](https://img.shields.io/github/stars/openhue/openhue-cli)](https://github.com/openhue/openhue-cli/stargazers)
 [![GitHub issues](https://img.shields.io/github/issues/openhue/openhue-cli)](https://github.com/openhue/openhue-cli/issues)
 [![GitHub](https://img.shields.io/github/license/openhue/openhue-cli)](https://github.com/openhue/openhue-cli/blob/main/LICENSE)