added github workflow

.github/workflows/build-test.yml

@@ -0,0 +1,22 @@
+name: Build and Test
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: macos-latest
+
+    steps:
+    - name: Checkout Code
+      uses: actions/checkout@v2
+
+    - name: Build Project
+      run: |
+        make all
+
+    - name: Clean Up
+      run: |
+        make clean

Makefile

@@ -80,7 +80,7 @@ bundle: all
 	@echo "$(MACOS_BUNDLE) bundle created"
 
 .DEFAULT:
-	@echo "Nothing to do. Please specify a target (e.g., 'make run')."
+	echo "Nothing to do. Please specify a target (e.g., 'make run')."
 
 mgba:
 	@mgba "$(ROM_PATH)/$(ROM_FILE)"