Update sync-readme-changelog.yml

Author: nsingh-branch

.github/workflows/sync-readme-changelog.yml

@@ -36,7 +36,7 @@ jobs:
             --header 'accept: application/json' \
             --header "authorization: Basic ${{ secrets.readme_api_key_base64 }}" \
             --header 'content-type: application/json' \
-            --header 'x-readme-version: v5.5.1'
+            --header 'x-readme-version: v5.5.1' \
             --data "$payload"
 
     - name: Announce New Release in Slack