8.8: Add a comment on why it's a silly example and a comment on what would happen in this code

[signekb]

Description

I think that it would be nice with a comment on the code to explicitly state why it's "silly"

r-cubed-intermediate/sessions/dplyr-joins.qmd

Lines 526 to 540 in ef26428

	used then by default, the final output would be a missing value. A
	(silly) example using age might be:
	```{r}
	#| eval: false
	case_when(
	age > 20 ~ "old",
	age <= 20 ~ "young",
	# For final condition
	TRUE ~ "unborn!"
	)
	```
	If instead you want one of the conditions to be `NA`, you need to set
	the appropriate `NA` value: