wrap_long_sentence: Line break after very long words
In Yutong441/TBdev: Infer a Trophoblast Developmental Trajectory

I could have used stringr::str_wrap but that function does not consider if the input string already has breaks

1	wrap_long_sentence(vec, index_sepa = ",", break_sepa = "\n", thres = 8)

`vec`	a character vector, e.g. `c('HLA-G','TBX3','CGA')`
`index_sepa`	where may a line break be inserted
`break_sepa`	the separator for line break, i.e. '\n' for most applications except `<br>` for markdown syntax.
`thres`	how many letters maximum in each line