Use Github Action as a release pipeline to Docker (#9720)

* Create main.yml

* Update and rename main.yml to docker.yml

.github/workflows/docker.yml

@@ -0,0 +1,42 @@
+# This is a basic workflow to help you get started with Actions
+
+name: Run Docker
+
+# Controls when the workflow will run
+on:
+  push:
+    branches:
+      - 'master'
+    tags:
+      - 'v*' 
+  workflow_dispatch:
+
+# A workflow run is made up of one or more jobs that can run sequentially or in parallel
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Inject slug/short variables
+        uses: rlespinasse/github-slug-action@v3.x
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+      - name: Login to Docker Hub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      - name: Build and push Docker images
+        # You may pin to the exact commit or the version.
+        # uses: docker/build-push-action@1bc1040caef9e604eb543693ba89b5bf4fc80935
+        uses: docker/build-push-action@v2.6.1
+        with:
+          image: ${{ secrets.DOCKERHUB_USERNAME }}/nodebb
+          platforms: linux/amd64,linux/arm64/v8,linux/arm/v7
+          push: true
+          # List of tags
+          tags: ${{ env.GITHUB_REF_SLUG }},${{ env.GITHUB_BASE_REF_SLUG }},${{ env.GITHUB_SHA_SHORT }}