add arm build actions

.github/dependabot.yml

@@ -0,0 +1,15 @@
+
+version: 2
+updates:
+  - package-ecosystem: "docker"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    reviewers:
+      - "tboeghk"
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    reviewers:
+      - "tboeghk"

.github/workflows/ci.yaml

@@ -0,0 +1,20 @@
+name: continuous integration
+
+on:
+  push:
+    branches:
+      - master
+      - main
+      - feature/**
+  pull_request:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: build Docker file
+        uses: docker/build-push-action@v5
+        with:
+          push: false

.github/workflows/release.yaml

@@ -0,0 +1,36 @@
+name: release
+on:
+  workflow_dispatch:
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to GitHub Docker Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - uses: actions/checkout@v4
+
+      - id: determine-tag
+        name: Determine Docker tag
+        run: echo "::set-output name=tag::$(date +%Y-%m-%d)"
+
+      - name: build Docker file
+        uses: docker/build-push-action@v5
+        with:
+          push: true
+          platforms: linux/arm64, linux/amd64
+          tags: |
+            ghcr.io/${{ github.repository }}:${{ env.build_tag }}
+            ghcr.io/${{ github.repository }}:latest