bug#12560: 24.2; newsticker group support undocumented

[Ulf Jasper]

"Max (☭)" <max@sec.t-labs.tu-berlin.de> writes:

> The newsticker RSS reader support creating groups and assigning feeds
> into groups. However no group file format nor functions to move/assign
> feeds into group are documented.
>
> Newsticker should supply example group file in the same way it supply
> example rss feeds. In addition to functions for feed assign/move there
> should be function to explicitly save group file otherwise this
> information is lost upon emacs exit.

I'll see to it.