Autobuild container with new code on main

.github/workflows/building-docker-autobuild.yml

@@ -0,0 +1,28 @@
+name: Build autobuild container that runs tests on dashboard.sitespeed.io
+on:
+  push:
+    branches:
+    - main
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        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: Build and push sitespeed.io
+        uses: docker/build-push-action@v2
+        with:
+          platforms: linux/amd64
+          push: true
+          tags: sitespeedio/sitespeed.io-autobuild:main