Improve slide output packing example comments

Co-authored-by: nmdefries <[email protected]>

R/slide.R

@@ -106,8 +106,8 @@
 #'
 #' # The tidyverse supports ["packing"][tidyr::pack] multiple columns into a
 #' # single tibble-type column contained within some larger tibble. Like dplyr,
-#' # we normally don't pack output columns together, but will if you provide a
-#' # name for a tibble-type output:
+#' # we normally don't pack output columns together. However, packing behavior can be turned on
+#' # by providing a name for a tibble-type output:
 #' cases_deaths_subset %>%
 #'   epi_slide(
 #'     slide_packed = tibble(