Read an Ontario-Catalogue XLSX data-dictionary sidecar.
Source:R/arsau_datasets.R
morie_arsau_read_xlsx_dictionary.RdSome ARSAU releases ship a companion *.xlsx file alongside
the CSV that holds the column-level data dictionary (variable name
dtype + notes). This helper reads the first sheet via readxl and normalises the column names to
name / type / notes. Requires the optional readxl dependency.