Description of problem:
The installation guide mentions the upgrade method "FedUp" as a possible way
to upgrade to Fedora 23.

https://docs.fedoraproject.org/en-US/Fedora/23/html/Installation_Guide/chap-preparing-for-installation.html#sect-preparing-upgrade-or-install

This information seems to be out of date, as there are instructions elsewhere  [1],[2] on using dnf for the system upgrade.

[1] Fedora Magazine
https://fedoramagazine.org/upgrading-from-fedora-22-to-fedora-23/
[2] Fedora Wiki
https://fedoraproject.org/wiki/DNF_system_upgrade

Version-Release number of selected component (if applicable):
install-guide

How reproducible:


Steps to Reproduce:
1. Navigate to https://docs.fedoraproject.org/en-US/Fedora/23/html/Installation_Guide/
2. Scroll down and select (click on) "3.1. Upgrade or Install?"
3. Read that section.

Actual results:
The preferred way to upgrade your system is an automatic upgrade using the FedUp utility. For information on performing an automatic upgrade, see Section 12.1, “Automatic System Upgrade Using FedUp”. 

Expected results:
Use 

Additional info: