[dev] @category tag

[Chuck Hagenbuch]

Quoting Jan Schneider <jan at horde.org>:

> Historically, @category is being used for the category a package is
> assigned to in PEAR. That doesn't make much sense for Horde packages
> unless they are in PEAR though, because we usually have only one
> package per "category".

Right... the idea, though, is that someone building docs for multiple  
projects doesn't have any other way of grouping docs by project.

-chuck