mine package descriptions from distributions

Many distributions provide descriptions (long and short) in the build files and/or package database for packages. For example on Fedora:

```
$ rpm -qi bash
Name : bash
[...]
Summary : The GNU Bourne Again shell
Description :
The GNU Bourne Again shell (Bash) is a shell or command language
interpreter that is compatible with the Bourne shell (sh). Bash
incorporates useful features from the Korn shell (ksh) and the C shell
(csh). Most sh scripts can be run by bash without modification.

```

It might be interesting to mine and store these descriptions for multiple distributions and make them available, for example to power a better package search engine.