[Rpm-metadata] simple docs

[seth vidal]

> I guess someone could change the internal storage for up2date to use
> metadata, or add repo backend for up2date - and transform that into
> the current internal metadata.
> 
> It'd be nice to get stuff going before test1 freeze.


eeek. ok that's 2 weeks for devel freeze. Worth a shot I guess. I'm
going to have to really move things in yum to make this work by then. I
should bug adrian to see if he thinks he can do it in that time. He
should be able to use the import code I wrote to get the data he needs.


-sv