support woodpecker ci

.woodpecker/image.yml

@@ -9,6 +9,7 @@ labels:
   platform: ${platform}
 steps:
   - name: build
-    image: debian
-    commands:
-      - echo "This is the build step; okay"
+    image: woodpeckerci/plugin-docker-buildx
+    settings:
+      repo: brosner.dev/brosner/teufa
+      tag: wp-${platform}