Remove irrelevant mentions of Tails Installer, post USB images
In https://tails.boum.org/doc/first_steps/persistence, it is said twice that one need a device installed with Tails installer in order to set up a persistent volume:
It is only possible to create a persistent volume if the USB stick was installed using Tails Installer.
Now that it is possible to install IMG images with Etcher, that’s not true anymore and should be fixed
Feature Branch: doc/16548-remove-tails-installer-mentions
- Blocks #15941 (closed)