Formats a numeric vector of probabilities as percentage
strings the way simulation summaries want them: values below 1% render as
"<1%" and values above 99.9% as ">99.9%", so a long-shot never reads
as a flat 0% and a near-lock never reads as a certain 100%. Exact 0
and exact 1 are left as "0%" and "100%".
Adapted from nflseedR's fmt_pct_special().
Examples
# \donttest{
fmt_pct_special(c(0, 0.0004, 0.123, 0.5, 0.9994, 1))
#> [1] "0%" "<1%" "12%" "50%" ">99.9%" "100%"
# }