@mgimenez maybe you can review this one? I used the same reference that we have in our README.md, this one: https://ieeexplore.ieee.org/document/7568429/citations#citations
There, you can find the citation formats (bibtex/etc) that help writing this file. As reference, I used the ecFlow's file: https://github.com/ecmwf/ecflow/blob/develop/CITATION (worth checking I didn't leave any copy-paste values unchanged).
Other refs: https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-citation-files & https://citation-file-format.github.io/
This is not urgent, so take your time to review this one
Thanks!