Add CI badge to README

Author: somestupidgirl

README.md

@@ -1,5 +1,6 @@
 # mSL/FHS
 
+[![C/C++ CI](https://github.com/somestupidgirl/mSL-FHS/actions/workflows/c-cpp.yml/badge.svg)](https://github.com/somestupidgirl/mSL-FHS/actions/workflows/c-cpp.yml)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 [![Platform](https://img.shields.io/badge/Platform-macOS-lightgrey)](#requirements)