[doc] pod/perlvar.pod: should the <<>> operator be mentioned more often?

[vaitkus]

Where
pod/perlvar.pod

Description
Multiple variables interact with the double diamond operator (<<>>) in the same way they interact with the single diamond operator (<>), e.g. $ARGV, ARGV, $., ${^OPEN}. However, only the ${^OPEN} description explicitly mentions <<>> ("or the related <> and <<>> operators"). I was wondering if it would be worthwhile to modify the other mentions in a similar way as well, e.g. by introducing phrasing like "<>/<<>> operators" instead of "<> operator". On the one hand it is more verbose, on the other, newcomers may not be aware of the <<>> operator at all as the majority of the coding examples in the wild probably use <>.