The human-oriented plan output includes a short summary of the meaning of
all of the different "icons" used to describe different kinds of change,
but nothing was previously describing how OpenTofu uses "->" to describe
the transition between current and planned values for update in-place, "~".
We'll now include a concise note about that as part of the icon summary,
keeping things still relatively compact but nonetheless giving something
to refer to if a reader is unsure about the meaning of this notation.
Signed-off-by: Martin Atkins <mart@degeneration.co.uk>
15272f8672