Update main.yml

.github/workflows/main.yml

@@ -10,6 +10,13 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
+    - name: Login to GitHub Container Registry
+      uses: docker/login-action@v3
+      with:
+        registry: registry.steffenillium.de/v2/
+        username: ${{ secrets.DOCKER_USER }}
+        password: ${{ secrets.DOCKER_PASS }}
+    
     - uses: actions/checkout@v4
     - uses: ruby/setup-ruby@v1
       with: