Enhance deployment workflow by saving Docker image as a tarball and uploading it as an artifact. Update AdminPage to provide user feedback for unsupported Docker export functionality.

.gitea/workflows/deploy.yml

@@ -18,7 +18,16 @@ jobs:
       - name: Build Docker image
         run: docker build -t markdownblog .
 
+      - name: Save Docker image as tarball
+        run: docker save markdownblog -o markdownblog-image.tar
+
+      - name: Upload Docker image artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: markdownblog-docker-image
+          path: markdownblog-image.tar
+
       - name: Push Docker image
-        run: docker push registry.gitea.com/user/markdownblog:latest
+        run: docker push 10.0.0.13:3002/rattatwinko/markdownblog:latest
 
       - name: Deploy to Gitea