Add publish-docker workflow

.github/workflows/publish-docker.yml

@@ -0,0 +1,30 @@
+name: publish-docker
+on:
+  push:
+    branches:
+      - 'master'
+      - 'develop'
+      - 'v2'
+jobs:
+  publish-docker:
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Login to Docker Registry
+        uses: docker/login-action@v2
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+      - name: Build
+        uses: docker/build-push-action@v3
+        with:
+          context: ./
+          file: ./Dockerfile
+          push: true
+          tags: ghcr.io/datagov-cz/data-validator:${{ github.ref_name }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max