change heading level for publication policy

Author: jchiquet

site/about.qmd

@@ -72,7 +72,7 @@ To ensure that all published information remains accessible and usable over time
 - we regularly run the workflow of each published article to check its medium- and long-term reproducibility;
 - we archive all git repositories of published articles on [Software Heritage](https://www.softwareheritage.org/) ![](../assets/img/logo-sh.png){height="20px"}.
 
-### Publication policy
+## Publication policy
 
 We would also like to emphasize that publishing an article in Computo in no way prevents authors from depositing a version of their article (e.g., PDF) in an institutional repository (e.g., HAL or arXiv), which helps to preserve and disseminate scientific work and is fully in line with the journal's policy and spirit. The only requirement is to fullfil the CC-BY license and to cite the original publication in Computo. This policy has been registered in the [Mir@bel](https://reseau-mirabel.info/revue/14421/Computo) and [Open Policy finder](https://openpolicyfinder.jisc.ac.uk/id/publication/46253) networks.