Add CITATION.cff file

[robyngit]

GitHub supports citation metadata via a CITATION.cff file. To improve discoverability and compatibility with citation tools, we should add a CITATION.cff file that references the existing DOI.

GitHub uses this file to show a "Cite this repository" button like so:

This file could also be used to help automate the release workflow (#2593) - it would give us a clean way to get the current DOI to download the existing datacite xml to update. In turn, the automated workflow could also update the CITATION.cff on new releases.

[mbjones]

Thanks, this is a great idea. The CFF metadata spec is a subset of the metadata in the CodeMeta (https://codemeta.github.io) software metadata spec that we have helped develop, and which GitHub originally supported for citation metadata. If Gtihub still supports codemeta.json for citation metadata for software, I'd prefer to use that format as it is schema.org compatible and is the direction that other groups like scicodes.net have adopted. Can you take a look at that as well when implementing here please?

[robyngit]

@mbjones too bad, it looks like GitHub. doesn't support codemeta.json:

Other citation files

The GitHub citation feature will also detect a small number of additional files that are often used by communities and projects to describe how they would like their work to be cited.

GitHub will link to these files in the Cite this repository prompt, but will not attempt to parse them into other citation formats.

Note these are case-insensitive and must be in the root of the repository
CITATION
CITATIONS
CITATION.bib
CITATIONS.bib
CITATION.md
CITATIONS.md