04-word-combinations: `library(ggplot2)` invisible

[mbeveridge]

Don't know if this is relevant (or my words/actions correct). In the past you've shown each library() action you need in that Section. But in this Section4 (s4.1.3 for the red-blue bar chart, etc) we can't see 'library(ggplot2) ahead of the ggplot() in original row175.

(library(ggplot2) does exist in row111, but "echo = FALSE" in row110 means that whole bloc (rows110-125) doesn't display in s4.1.2 of [https://www.tidytextmining.com/ngrams.html] ...though Figure 4.1 does)

[juliasilge]

Thanks so much, @mbeveridge! 🙌