(Slightly) broken html doc

[Akim Demaille]

Hi!

You might already know this, but 
https://www.gnu.org/software/gnulib/manual/html_node/index.html shows the 
documentation of the ‘index’ module at its bottom.  It smells like a problem in 
makeinfo.  The page was used with Texinfo 6.3.  I tried to reproduce it with 
Texinfo 6.5, but then the index.html I get is really the index, not the front 
page of the documentation.

I had run

$    make updated-stamp
$ ../build-aux/gendocs.sh \
     -I ../build-aux \
     --email address@hidden \
     -o "/tmp/manual" \
     gnulib "The GNU Portability Library"


Cheers!