v0.2.0 2021-04-25 Cambridge

• Add a fields_to_yaml function to convert the internal field data representation to a Yaml.value (#2 @patricoferris)
• find now returns a Yaml.value option rather than a string option (#1 @patricoferris)
• port to dune (@avsm)
• use Yaml library to parse front matter instead of a homebrew parser. (@avsm)
• use ocamlformat 0.18.0 (@avsm)
• minimum OCaml version supported is now 4.05+ (@avsm)