dfm() Rd still includes ngrams argument

[kbenoit]

We need to remove the ngrams argument from the examples for dfm(). They're not executing and producing warnings instead.

featnames(dfm(corp, ngrams = 2, select = stopwords("english"), remove_punct = TRUE))
#> Warning: ngrams argument is not used.
#> [1] "the"  "over" "with" "from" "a"    "in"   "his" 

The error is from

quanteda/R/dfm.R

Lines 84 to 85 in e16b4ba

	#' featnames(dfm(corp, ngrams = 2, select = stopwords("english"), remove_punct = TRUE))
	#' featnames(dfm(corp, ngrams = 1:2, select = stopwords("english"), remove_punct = TRUE))