Add submodule-init (#283)

* Change target repo

* Add latest tag

.github/workflows/build.yaml

@@ -0,0 +1,45 @@
+### This workflow build and push image ###
+name: Multi-arch build 
+
+on:
+  push:
+    tags:
+      - "v*"
+      
+jobs:
+  build:
+    name: Build 
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code 
+        uses: actions/checkout@v2
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+
+      - name: Set up Docker Buildx
+        id: buildx
+        uses: docker/setup-buildx-action@v2
+
+      - name: Available platforms
+        run: echo ${{ steps.buildx.outputs.platforms }}
+     
+      - name: Login to Docker Hub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKER_HUB_USERNAME }}
+          password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
+
+      - name: Get Tag Name
+        id: tag_name
+        run: |
+          echo ::set-output name=SOURCE_TAG::${GITHUB_REF#refs/tags/}
+
+      - name: Submodules init
+        run: git submodule update --init
+
+      - name: Build multiarch docs-example
+        run: |
+          DOCKER_TAG=$(echo ${{ steps.tag_name.outputs.SOURCE_TAG }} | sed 's/^.//')
+          docker buildx build -t onlyoffice/docs-example:$DOCKER_TAG \
+          -t onlyoffice/docs-example:latest --platform linux/amd64,linux/arm64 --push web/documentserver-example/nodejs/.