FEATURE (docker): Build project for sending to Docker hub

.github/workflows/docker.yml

@@ -0,0 +1,36 @@
+name: Build & push Docker image
+
+on:
+  push:
+    branches: [main]
+  workflow_dispatch: {}
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v4
+
+      - name: Set up QEMU (enables multi-arch emulation)
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          platforms: linux/amd64,linux/arm64 # both chip families
+          tags: |
+            rostislavdugin/postgresus:latest
+            rostislavdugin/postgresus:${{ github.sha }}