logical; if TRUE return a simple vector, if
FALSE return a list if the original word list was nested
a character vector containing the stopwords, or a list
of characters simplify = FALSE
The language codes for each stopword list use the two-letter ISO
code from https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes.
For backwards compatibility, the full English names of the stopwords
from the quanteda package may also be used, although these are