Hello, might be of interest to you (and yes, it includes front matter in YAML too). I've started a collection of inline meta data formats (that are supported by the csvreader library in ruby). For now the formats include: CSV in CSV, Attribute-Relation "Classic", Attribute- Relation "Inline" and, yes, front matter in YAML.
See https://github.com/csvspecs/csv-meta for all formats. Cheers. Prost.