Bug#722636: mention how to use $# sigil with array references

[jidanni at jidanni.org]

>>>>> "RA" == Russ Allbery <rra at debian.org> writes:

RA> It's documented in perldata under Scalar Values, about seven paragraphs
RA> down.  (And yeah, it's not horribly easy to find.)

Ah, right near where he mentions csh (wonder how many kids know what that is).

P.S.
Besides discovering I could use $#$$, I now also find $#{$$ ... works,
    use Data::Dumper; die Dumper ($#{$$p{$g}{members}{data}},$$p{$g}{members}{data}[0]);
so also document that too please there on perlref. Yes it is starting to look !@#$ing ugly!