generate_html: New characteristic - install/load field in the index file of the online documentation

[TrucomanX XnamocurT]

I am writing to call your attention and ask for your comments about a pacth that I am proposing.

https://savannah.gnu.org/patch/?8988

This shows the installation/loading commands in the index page of reference manual.

You can see an example of this modification in the next site.

http://nongnu.org/bsltl/bsltl_refman/bsltl/index.html

I think that this is important, given that the octave packages are unloaded by default.
And many people don't know how make install/load this in the command line.

Given that, the reference manual is the first information found in the searches of web. It is very important to have a clear explication about this.

The patch can be download of :

https://savannah.gnu.org/support/download.php?file_id=37062

Fernando