Generate Citation File Format (CFFs) for case studies

[balacij]

The CFF files use a YAML encoding of metadata about the software project. So, in order for us to do this, it would be good to make a YAML v1.2 compatible printer first.

CFF: https://github.com/citation-file-format/citation-file-format/blob/main/README.md Specifications: https://github.com/citation-file-format/citation-file-format/blob/main/schema-guide.md

This is a note from a past meeting where we discussed CFFs briefly, but I don't think we followed up on it.