ci: publish Docker images to ghcr.io

.github/workflows/dockerhub.yml

@@ -38,6 +38,7 @@ jobs:
         uses: docker/metadata-action@v3
         with:
           images: |
+            ghcr.io/nginx-proxy/nginx-proxy
             nginxproxy/nginx-proxy
             jwilder/nginx-proxy
           tags: |
@@ -60,6 +61,13 @@ jobs:
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
+          
+      - name: Log in to GitHub Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Build and push the Debian based image
         if: github.ref == 'refs/heads/main'