[gtk4] Update help pages
#7804 (closed) continued, sort of
With the UI changes of the gtk4 version, especially in the Prefs dialog, the help pages need to be updated.
It's mostly the sentences like
In the sidebar, select your current profile in the Profiles section.
that need to be updated, plus the whole "Manage profiles" page.
Also any new or removed feature (let's say Pinned tabs).