chore(readme): add ci/cd badge

README.md

@@ -1,6 +1,8 @@
-# Branch Blockchain 🟩
+# ⛓️ Branch Blockchain
 
-Repository for the blockchain branch.
+[![🐳 On Master - Build and Test Docker Image](https://github.com/01-edu/Branch-Blockchain/actions/workflows/ga-image-build-master.yml/badge.svg?branch=master)](https://github.com/01-edu/Branch-Blockchain/actions/workflows/ga-image-build-master.yml)
+
+Repository for the blockchain branch content and tests.
 
 ## Content 📖
 
@@ -59,4 +61,4 @@ docker run -it --entrypoint /bin/bash blockchain:latest
 
 ## Authors ✍️
 
-Xavier Lavayssière - [🐙](https://github.com/Xalava) [🐦](https://twitter.com/xavierlava)
+Xavier Lavayssière - [🐙](https://github.com/Xalava) [🐦](https://twitter.com/xavierlava)