ci: push to ghcr.io (#10)

.github/workflows/docker.yaml

@@ -23,7 +23,7 @@ jobs:
         with:
           # list of Docker images to use as base name for tags
           images: |
-            acouvreur/traefik-ondemand-service
+            ghcr.io/acouvreur/traefik-ondemand-service
           # generate Docker tags based on the following events/attributes
           tags: |
             type=schedule
@@ -40,7 +40,7 @@ jobs:
         name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v1
       -
-        name: Login to DockerHub
+        name: Login to ghcr.io
         uses: docker/login-action@v1 
         with:
           registry: ghcr.io