[O] htmlize

[Jean-Christophe Helary]

I tried to export to html and org told me to first install htmlize ( 
https://github.com/hniksic/emacs-htmlize).

I tried to find an emacs-htmlize in the package list, and found nothing, so I 
went to the github page and since  saw it was a seemingly normal el package 
called htmlize I checked again in the packages, found it and installed it 
directly from emacs.

Why doesn't org suggest to use package.el to install htmlize? That would be 
less confusing to users who don't have it installed by default.

Jean-Christophe