Add multi-registry push to Snapshot images

.github/workflows/build-snapshot.yml

@@ -37,18 +37,26 @@ jobs:
         id: buildx
         uses: docker/setup-buildx-action@v1
 
-      - name: Log into registry ${{ env.REGISTRY }}
+      - name: Log into ${{ env.GH_REPO }} registry
         uses: docker/login-action@v1
         with:
           registry: ${{ env.GH_REPO }}
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
           
+      - name: Log into DockerHub registry
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
       - name: Extract Docker metadata
         id: meta
         uses: docker/metadata-action@v3
         with:
-          images: ${{ env.GH_REPO }}/${{ env.IMAGE_NAME }}
+          images: |
+            ${{ env.GH_REPO }}/${{ env.IMAGE_NAME }}
+            ${{ env.IMAGE_NAME }}
       
       - name: Build image and push snapshot to GitHub Container Registry
         id: build-and-push