[Rpm-maint] [rpm-software-management/rpm] Correct and update Query formats documentation (#827)

[pavlinamv]

Moreover to the described corrections (according to the review) I add an example of example of a query expression.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/rpm-software-management/rpm/pull/827#issuecomment-529451544
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.rpm.org/pipermail/rpm-maint/attachments/20190909/19a1d93f/attachment.html>