Add header to PR preview message

Signed-off-by: Raunak Madan <143412156+CodexRaunak@users.noreply.github.com>

Author: CodexRaunak

.github/workflows/build-and-preview-docs.yml

@@ -94,6 +94,7 @@ jobs:
           header: pr-preview
           message: |
             🚀 Preview deployment: https://${{ github.repository_owner }}.github.io/${{ github.event.repository.name }}/pr-preview/pr-${{ github.event.pull_request.number }}/
+            
       - name: Cleanup PR preview on close
         if: github.event.action == 'closed'
         uses: rossjrw/pr-preview-action@v1.6.3