duplicate build for docker hub (#134)

.github/workflows/publish.yml

@@ -12,7 +12,7 @@ on:
       - 'main'
 
 jobs:
-  docker-build:
+  docker-build-ghcr:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -25,6 +25,22 @@ jobs:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
+      - uses: docker/build-push-action@v5
+        with:
+          context: .
+          platforms: linux/amd64
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          outputs: type=image,name=target,annotation-index.org.opencontainers.image.description=See https://github.com/protomaps/go-pmtiles for more info.
+  docker-build-dockerhub:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: docker/metadata-action@v5
+        id: meta
+        with:
+          images: protomaps/gi-pmtiles
       - uses: docker/login-action@v3
         with:
           username: protomaps