remove spoiler callout to make a forecast plot

[avallecam]

In this episode section: https://epiverse-trace.github.io/tutorials-middle/create-forecast.html#forecasting-secondary-observations

We added this temporal patch:

tutorials-middle/episodes/create-forecast.Rmd

Lines 358 to 384 in d2d3aee

	:::::::::::::::: spoiler
	### make a forecast plot
	```{r}
	deaths_forecast %>%
	purrr::pluck("predictions") %>%
	ggplot(aes(x = date, y = secondary)) +
	geom_col(
	fill = "grey", col = "white",
	show.legend = FALSE, na.rm = TRUE
	) +
	geom_ribbon(aes(ymin = lower_90, ymax = upper_90),
	alpha = 0.2, linewidth = 1) +
	geom_ribbon(aes(ymin = lower_50, ymax = upper_50),
	alpha = 0.4, linewidth = 1) +
	geom_ribbon(aes(ymin = lower_20, ymax = upper_20),
	alpha = 0.6, linewidth = 1) +
	theme_bw() +
	labs(y = "Reports per day", x = "Date") +
	scale_x_date(date_breaks = "week", date_labels = "%b %d") +
	scale_y_continuous(labels = scales::comma) +
	theme(axis.text.x = ggplot2::element_text(angle = 90))
	```
	::::::::::::::::

Remove it after this issue in EpiNow2 gets fixed epiforecasts/EpiNow2#702