This function writes an object of class fnames to a text file. Each filename
is written in a separate line. The file encoding is always "UTF-8".
In addition, it can store metadata in an additional configuration file.
Arguments
- x
- Object of class - fnames.
- file
- Path to output file. 
- ...
- Additional arguments (not implemented). 
See also
Other writing functions: 
write_assoc(),
write_conc(),
write_freqlist(),
write_tokens(),
write_txt(),
write_types()
