Spin.Config_file_usertype cst = | Name of Base.string| Email of Base.string| Github_username of Base.string| Npm_username of Base.stringval cst_of_sexp : Sexplib0.Sexp.t -> cstval sexp_of_cst : cst -> Sexplib0.Sexp.ttype t = {name : Base.string Base.option;email : Base.string Base.option;github_username : Base.string Base.option;npm_username : Base.string Base.option;}type doc = tval save : t -> from_dir:Base.string -> Base.unit