chore(docker): add Docker image build. Thanks @pexcn for the contributions!

Co-authored-by: Datong Sun <dndx@idndx.com>

.github/workflows/docker.yml

@@ -0,0 +1,30 @@
+name: Docker image build
+
+on:
+  push:
+    paths-ignore:
+      - '**.md'
+
+jobs:
+  build:
+    runs-on: ubuntu-22.04
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Setup QEMU
+        uses: docker/setup-qemu-action@v2
+        with:
+          platforms: linux/amd64
+
+      - name: Setup Docker Buildx
+        uses: docker/setup-buildx-action@v2
+
+      - name: Build Docker Image
+        uses: docker/build-push-action@v3
+        with:
+          context: .
+          file: docker/Dockerfile
+          tags: phantun
+          platforms: linux/amd64