Creates ppi metadata
Examples
if (FALSE) { # \dontrun{
url <- "https://www.ons.gov.uk/file?uri=/economy/inflationandpriceindices/
datasets/consumerpriceindices/current/ppi.csv"
tmp <- tempfile()
download.file(url, tmp)
rawfile <- tmp
get_ppi_metadata(rawfile)
} # }