Multi-arch Docker builds (#1111)

* Multiarch Docker builds

* Setup QEMU for multiarch builds

* Publish multiarch containers

Author: kyleconroy

.github/workflows/docker.yml

@@ -2,7 +2,7 @@ name: docker
 on:
   push:
     branches:
-    - main
+      main
 jobs:
   docker:
     name: push kjconroy/sqlc:devel
@@ -14,6 +14,7 @@ jobs:
         echo ::set-output name=created::$(date -u +'%Y-%m-%dT%H:%M:%SZ')
     - uses: actions/checkout@v2.3.4
     - uses: docker/setup-buildx-action@v1
+    - uses: docker/setup-qemu-action@v1
     - uses: docker/login-action@v1.10.0
       with:
         username: kjconroy
@@ -22,6 +23,7 @@ jobs:
       with:
         context: .
         file: ./Dockerfile
+        platforms: linux/amd64,linux/arm64/v8
         build-args: |
           github_ref=${{ github.ref }}
           github_sha=${{ github.sha }}