Update README.md

Author: Gabriele Nava

README.md

@@ -1,5 +1,7 @@
 # whole-body-controllers
 
+[![CI_WBC](https://github.com/robotology/whole-body-controllers/actions/workflows/ci_wbc.yml/badge.svg)](https://github.com/robotology/whole-body-controllers/actions/workflows/ci_wbc.yml)
+
 **Warning! This repository contains reseach material and therefore is under active development. In future releases, `master` branch may break compatibility with older versions of WBC. If you are interested in retrieving a `stable` version of this repo, `fork the repository` or refer to the following releases:**
 
 - [WBC v2.5](https://github.com/robotology/whole-body-controllers/releases/tag/v2.5)