Add build status badge to README

Author: darbyluv2code

README.md

@@ -1,5 +1,7 @@
 # Java Programming Introduction for Beginners
 
+[![Build Status](https://github.com/darbyluv2code/java-programming-introduction-for-beginners/actions/workflows/build.yml/badge.svg)](https://github.com/darbyluv2code/java-programming-introduction-for-beginners/actions/workflows/build.yml)
+
 Source code for the course: [*Java Programming Introduction for Beginners*](https://www.luv2code.com/java-intro-github)
 
 If you have questions or need tech support, post your questions to the [classroom discussion forum](https://www.luv2code.com/java-intro-github).