fix(#9): Implement CI-Workflow for Docker tests on push and PR

.github/workflows/docker-test.yml

@@ -0,0 +1,23 @@
+name: Docker Test
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+      
+    - name: Build Docker image
+      run: |
+        docker build -f Dockerfile.test -t test-image .
+        
+    - name: Run tests in container
+      run: |
+        docker run --rm test-image npm test