In the general scheme of things I've set up a local Wiki (TikiWiki) that I copy important items to. While it doesn't automatically update as changes are made to things like the config file, it does offer storage that is secure against any number of problems**, provides a way to keep historical versions of non-versioned files, and a convenient place to include information about why the file is important, where it came from, what the content format is, and why certain option in the file were selected.
It also makes it easy to cross-link to both official and ad hoc documentation.
I still feel as giddy about Wikis for this purpose as I did when I first saw PTC Pro/Engineer from years of working on CADDS IV wireframe models.
Perhaps not as relevant for you, but in larger companies it is so easy for one guy in charge of things to puzzle something out and forget where it was he put notes about it when a problem comes up a few years later, especially if that guy is a new guy taking over from someone else.
**The main thing is that the default Wiki information viewer is not an editor. View a text file with Notepad - it defaults to being able to edit it; same with Word, Excel, Pro/E. With Wikis, the default is just to display or just to export. No matter what the user does, they can't accidently change anything. And when they do change something, that something is automatically a new version; the old version is still available unless specifically deleted, which is a controllable ability via the Admin.
