[arch-releng] Use pandoc instead of make-doc.sh

[Dario Giovannetti]

I would like to propose using pandoc ( http://johnmacfarlane.net/pandoc/ 
) instead of the make-doc.sh script for converting the installation 
guide (Markdown syntax) to the document hosted in the wiki (MediaWiki 
syntax).
I've tested it and the result looks pretty good, with only a few minor 
manual refinements required (which I volunteer to perform, if needed): 
instead of the current script, which practically produces an html 
document, we would get a correctly-formed, much neater MediaWiki document.
This would greatly simplify further improvements in the wikification of 
the the guide, like the adaptation to ArchWiki's style standars.

Thank you
Dario