docs: create a 95% confidence interval of the mean

[davidhodge931]

library(tidyverse)
library(ggblanket)

set_blanket()

tidyplots::time_course %>%
  gg_lineribbon(
    x = day, 
    y = score,
    col = treatment,
    stat = "summary",
    blend = "multiply",
    fun.data = \(x) mean_se(x, mult = 1.96),
    coord = coord_cartesian(ylim = c(0, NA)),
  )