Add github workflow.

Author: rangoku

.github/workflows/containers.yaml

@@ -0,0 +1,32 @@
+name: Build and Push Docker Images
+
+on:
+  push:
+    branches: ["main"]
+
+jobs:
+  docker-build-push:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKER_HUB_USERNAME }}
+          password: ${{ secrets.DOCKER_HUB_TOKEN }}
+
+      - name: Build and push backend
+        uses: docker/build-push-action@v5
+        with:
+          context: ./packages/backend
+          push: true
+          tags: ${{ secrets.DOCKER_HUB_USERNAME }}/backend:latest
+
+      - name: Build and push frontend
+        uses: docker/build-push-action@v5
+        with:
+          context: ./packages/frontend
+          push: true
+          tags: ${{ secrets.DOCKER_HUB_USERNAME }}/frontend:latest