feat(docker): publish additionally to GitHub container registry (#631)

Author: joschi

.github/workflows/release.yml

@@ -53,11 +53,17 @@ jobs:
         uses: docker/setup-qemu-action@v3
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
-      - name: Login to DockerHub
+      - name: Login to Docker Hub
         uses: docker/login-action@v3 
         with:
           username: ${{ secrets.DOCKER_HUB_USERNAME }}
           password: ${{ secrets.DOCKER_HUB_PASSWORD }}
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build & Push Docker image
         uses: docker/build-push-action@v5
         with:
@@ -67,3 +73,5 @@ jobs:
           tags: |
             openapitools/openapi-diff:${{ github.event.inputs.releaseVersion }}
             openapitools/openapi-diff:latest
+            ghcr.io/openapitools/openapi-diff:${{ github.event.inputs.releaseVersion }}
+            ghcr.io/openapitools/openapi-diff:latest