Toy Examples? #9
Description
Perhaps an example such as your here-present "toy" data.frame/tibble/tribble would play well in section 2.8, where you mention data.frames for the first time. Maybe give a newbie a chance to interact with the data.frame construct.
This "toy" example has few rows or columns, so, whatever you do to/with it will entirely fit on a screen as you write about group_by(), and its dplyr associates. The larger mtcars, starwars, iris, etc, can come later after some confidence is built.