or mkdoc, filename, outname, lpp
alphabetizes and indexes the DOCUMENT comments in FILENAME, and
formats into "dictionary-like" pages for printing. If OUTNAME
is not given or nil, the output file will be FILENAME with ".doc"
replacing the ".i". If LPP is not given, it defaults to 58 --
the maximum number of available lines per page of output.
(Use 55 to be able to print with "lpr -p" style page headings.)
FILENAME can be an array of strings to combine several include
files into a single document.
interpreted function, defined at i/mkdoc.i line 10