feat: add gh action to build arm64 docker images

.github/workflows/image.yml

@@ -0,0 +1,29 @@
+name: buildx
+
+on:
+  pull_request:
+    branches: develop
+  push:
+    branches: develop
+
+jobs:
+  buildx:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      # https://github.com/docker/setup-qemu-action
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      # https://github.com/docker/setup-buildx-action
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      - name: Available platforms
+        run: echo ${{ steps.buildx.outputs.platforms }}
+      # not pushing to dockerhub for now
+      - name: Run Buildx
+        run: |
+          docker buildx build \
+            --platform linux/amd64,linux/arm64 \
+            --output "type=image,push=false" \
+            --file ./docker/Dockerfile .