add buildx to pipeline

.github/workflows/pipeline.yml

@@ -27,6 +27,9 @@ jobs:
 
   publish-container:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        platform: [linux/amd64, linux/arm64]
     needs: build-and-test
     if: github.ref == 'refs/heads/main'
     steps:
@@ -49,10 +52,14 @@ jobs:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
 
       - name: Build and push docker image with playground
         uses: docker/build-push-action@v2
         with:
+          platforms: ${{ matrix.platform }}
           context: ./
           tags: |
             lucasgaitzsch/pdf-turtle:latest
@@ -68,6 +75,7 @@ jobs:
       - name: Build and push docker image with playground and unprivileged
         uses: docker/build-push-action@v2
         with:
+          platforms: ${{ matrix.platform }}
           file: ./Dockerfile.unprivileged
           context: ./
           tags: |
@@ -80,6 +88,7 @@ jobs:
       - name: Build and push docker image without playground
         uses: docker/build-push-action@v2
         with:
+          platforms: ${{ matrix.platform }}
           file: ./Dockerfile.withoutPlayground
           context: ./
           tags: |