feature: add actions workflow to build

.github/workflows/main.yaml

@@ -0,0 +1,39 @@
+name: Main
+
+on:
+  push:
+    branches:
+      - main
+      - master
+
+env:
+  REGISTRY_NAME: container.localdomain:5000
+
+jobs:
+  build:
+    runs-on: docker
+    container:
+      image: catthehacker/ubuntu:act-22.04
+    steps:
+      - uses: RouxAntoine/checkout@v3.5.4
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2.9.1
+        with:
+          config-inline: |
+            [registry."${{ env.REGISTRY_NAME }}"]
+              http = true
+
+      - name: Build and push
+        uses: docker/build-push-action@v4
+        env:
+          ACTIONS_RUNTIME_TOKEN: '' # See https://gitea.com/gitea/act_runner/issues/119
+        with:
+          context: .
+          push: true
+          tags: ${{ env.REGISTRY_NAME }}/dnscrypt-proxy:latest
+          platforms: |
+            linux/arm/v6