Enhance PR preview message with deployment info

Added a note about preview deployment timing and tracking.

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

Author: CodexRaunak

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

@@ -86,6 +86,7 @@ jobs:
           header: pr-preview
           message: |
             🚀 Preview deployment: https://${{ github.repository_owner }}.github.io/${{ github.event.repository.name }}/pr-preview/pr-${{ github.event.pull_request.number }}/
+            > *Note: Preview may take a moment (GitHub Pages deployment in progress). Please wait and refresh. Track deployment [here](https://github.com/${{ github.repository }}/actions/workflows/pages/pages-build-deployment)*
 
       - name: Cleanup PR preview on close
         if: github.event.action == 'closed'