The current maintainer is Eric Rostetter, assisted by the rest of the Horde developers and users.
Well, there's nothing stopping you from doing so. We'd much prefer that you'd link to the master copy instead; that way, you're always sure to have the most recent version.
If you do want to mirror it, give the FAQ maintainer a shout so you can get the PHP source, rather than just the resulting HTML.
The canonical location for the FAQ is http://www.horde.org/faq/.