Add HYDAT citation function about tidyhydat

[boshek]

Something like this:|

hy_citation <- function() {
  title <- paste0(
    "Extracted from Environment and Climate Change Canada’s HYDAT.sqlite, released on ",
    as.Date(hy_version()$Date)
  )
  
  
  bibentry(
    bibtype = "Manual",
    title = title,
    author = person("Environment and Climate Change Canada"),
    year = format(hy_version()$Date, "%Y"),
    url = "https://collaboration.cmc.ec.gc.ca/cmc/hydrometrics/www/"
  )
}