add multiplatform build

.github/workflows/main.yml

@@ -0,0 +1,48 @@
+name: ci
+
+on:
+  push:
+    branches:
+      - 'master'
+
+jobs:
+  dockerhub-build-push:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v2
+      -
+        name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      -
+        name: Login to DockerHub
+        uses: docker/login-action@v1 
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      -
+        name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          platforms: linux/amd64,linux/arm64,linux/arm/v7
+          push: true
+          tags: ${{ secrets.DOCKERHUB_REPOSITORY }}:github
+  dockerhub-sync-readme:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Sync README
+        uses: docker://lsiodev/readme-sync:latest
+        env:
+          DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
+          DOCKERHUB_PASSWORD: ${{ secrets.DOCKERHUB_TOKEN }}
+          GIT_REPOSITORY: ${{ github.repository }}
+          DOCKER_REPOSITORY: ${{ secrets.DOCKERHUB_REPOSITORY }}
+          GIT_BRANCH: master
+        with:
+          entrypoint: node
+          args: /opt/docker-readme-sync/sync