Locally it rendered for me with the title of the target document, however when
deployed it rendered with the filename of the target document. So include the
document titles explicitly instead.
* Improve messaging regarding N->N+2 upgrades.
* Move some details regarding Rawhide issues to the specific Rawhide wiki page.
This generic guide doesn't need to go into detail about Rawhide issues,
because that makes it harder to read for general users (not interested in
Rawhide). Power users can follow a link.
* Update gnome-software screenshot (more recent, with graphics).
* Clearly state that upgrading using pure `dnf` or `fedora-upgrade` is
unsupported.
* Other small adjustments and clarifications, link fixes. Make section headlines
look consistent across articles (don't capitalize every word).
