Update github workflow

Author: reeshavacharya

.github/workflows/docker-image.yml

@@ -15,6 +15,12 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v1
 
+      - name: Get latest Token Registry API Tag
+        id: get_latest_tag
+        run: |
+          latest_tag=$(curl -s https://api.github.com/repos/cardanoapi/token-registry-api/releases/latest | jq -r .tag_name)
+          echo "::set-output name=tag::$latest_tag"
+
       - name: Log in to GitHub Container Registry
         uses: docker/login-action@v1
         with: