build container for arm64

.github/workflows/build.yml

@@ -45,6 +45,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v2
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
       - name: Docker meta
         id: meta
         uses: crazy-max/ghaction-docker-meta@v2