WIP: in tree Dockerfile and github actions push to github registry

.github/workflows/container.yml

@@ -0,0 +1,31 @@
+name: Build and publish Docker image
+
+on:
+  push:
+    branches:
+    - 'master'
+    - 'github-actions'
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          platforms: linux/amd64
+          push: true
+          tags: |
+            px4/px4-dev:latest
+            ghcr.io/px4/px4-dev:latest
+
+      - name: Image digest
+        run: echo ${{ steps.docker_build.outputs.digest }}