Convert .flextext file from FLEX to a dataframe.
flextext_to_df(file_name)
string with a filename or path to the .flextext file
a dataframe with columns: p_id, s_id, w_id, txt, cf, hn, gls, msa, morph, word, phrase, paragraph, free_trans, text, text_title
p_id
s_id
w_id
txt
cf
hn
gls
msa
morph
word
phrase
paragraph
free_trans
text
text_title