ci: add release process

Author: vincenzopalazzo

.github/workflows/release.yml

@@ -0,0 +1,40 @@
+name: Release
+
+on:
+  release:
+    types: [created]
+    tags:
+      - v*
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v2
+
+      -
+        name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      -
+        name: Login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      -
+        name: Set output
+        id: vars
+        run: echo ::set-output name=tag::${GITHUB_REF#refs/*/}
+      -
+        name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          platforms: linux/amd64
+          push: true
+          tags: vincenzopalazzo/ln-dashboard:${{ steps.vars.outputs.tag }}