Follow the example more closely

.github/workflows/build.yml

@@ -10,6 +10,12 @@ jobs:
   docker:
     runs-on: ubuntu-latest
     steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
       - name: Login to Docker Hub
         uses: docker/login-action@v2
         with: