build docker image using predefined action

.forgejo/workflows/build-jekyll.yml

@@ -6,7 +6,7 @@ jobs:
   build_website:
     runs-on: docker
     container:
-      image: git.hswro.org/fleg/hswro_org:latest
+      image: git.hswro.org/fleg/hswro_org_build:latest
     steps:
       - uses: actions/checkout@v3
         with:
@@ -18,9 +18,16 @@ jobs:
   build_and_push_container:
     runs-on: docker
     container:
-      image: git.hswro.org/fleg/hswro_org:latest
+      image: ubuntu-latest
     steps:
-      - uses: actions/download-artifact@v3
+      - uses: actions/checkout@v3
+      - 
+        name: Login to Docker Hub
+        uses: docker/login-action@v3
         with:
-      - run: find
-      - run: podman version
+          registry: git.hswro.org
+          username: ${{ github.actor }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      - 
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3