Added canary build action. Not tested yet

.github/workflows/canary-docker-build.yml

@@ -0,0 +1,29 @@
+name: Canary Docker Build
+
+on:
+  workflow_dispatch:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    types:
+      - closed
+    branches: [ "main" ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      - name: Login into docker hub
+        run: docker login -u ${{ secrets.DOCKER_USER }} -p ${{ secrets.DOCKER_PW }}
+      - name: Build and Push Docker image
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          file: ./Moonlight/Dockerfile
+          push: true
+          tags: moonlightpanel/moonlight:canary
+          platforms: linux/amd64,linux/arm64