[CentOS-docs] copying upstream docs to centos.org

On Thu, 2010-06-03 at 10:15 +0200, Tru Huynh wrote:
> ...
> I don't think that Red Hat as provided any updated guide, if we are
> missing any please point them here or add them to bugs.centos.org.

According to http://www.redhat.com/docs/manuals/enterprise/,
Installation Guide was published Mar 2010 and has a 5.5 link.  I haven't
compared actual content, though.

Even if there haven't been any updates to guide content, we should link
the guides under 5.5 so people don't think our guides are out-dated.
Out-dated guides are an indirect indication of inadequate project
resources.