Prevents copying something different from what was linked, such as in the
message "fine.gif https://example.com"

Two of the recommended plugins got merged in 1.4, and don’t exist any longer,
and when using flatpak the plugins must be installed that way.

fixes #4353

* Create migrating_to_new_device.md

* Add link to Readme for further information.

* Added some info

* Make separate backup guide and integrate Readme information with new guides.

Co-authored-by: Licaon_Kter <licaon-kter@users.noreply.github.com>

fixes #4321

fixes #4338

fixes #4351
fixes #4261

...but why was that function created elsewhere if here you just compare this?