ci: set up docker publishing to GHCR

.github/workflows/docker.yml

@@ -0,0 +1,43 @@
+name: Publish docker images
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+  workflow_dispatch:
+    inputs:
+      push:
+        description: 'Push to registry'
+        required: false
+        default: 'false'
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ github.token }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ghcr.io/${{ github.repository }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: ./Dockerfile
+          push: ${{ github.event_name == 'push' || github.event.inputs.push == 'true' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}