As the log-in prompt no longer shows on the first visit and the
landing page now has documentation, the relevant screenshot and
paragraphs are updated accordingly.
Other full-page screenshots are re-done, and will not show the browser
address bar - for simplicity and consistency.
We could also add screenshots of the "Token management" pop-up which
shows when the user heads to editing before logging in, and the same
pop-up when the user has logged in but isn't authorized to access the
survey. However, this would take more vertical space (more scrolling)
and it is probably sufficient to describe that in two short
paragraphs, as done currently. The logged-in-but-unauthorized
situation should not happen if the users are managed correctly.