insist on HTML availability and rendering

Author: jchiquet

site/guidelines-authors.qmd

@@ -48,6 +48,7 @@ This document provides a comprehensive documentation to accompany the authors du
 
 - **Publishing**:
   - Push changes to GitHub; CI will build and deploy the site.
+  - Ensure that both PDF and HTML versions render correctly.
   - Submit the PDF and repository link to [OpenReview](https://openreview.net/group?id=Computo).
   - Ensure that the HTML is publicly accessible for reviewers on the GitHub Pages site.