Fix Docker build command syntax in workflow

Author: Programeerik

.github/workflows/docker-build-frontend.yml

@@ -11,4 +11,5 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: Build the Frontend Docker image
-        run: docker build ShowcaseProject --file ShowcaseProject/ShowcaseFrontend/Dockerfile --tag my-image-name:$(date +%s)
+        run: |
+          docker build ShowcaseProject --file ShowcaseProject/ShowcaseFrontend/Dockerfile --tag my-image-name:$(date +%s) ShowcaseProject