Reword

- ATM there's only one production version of Perl 6 and it has the described semantics
- Remove mention of Perl 5, to avoid implication of it being the "previous version."
    The way Perl 5 does things is a concern for 5-to-6 docs.

Author: zoffixznet

doc/Language/containers.pod6

@@ -239,8 +239,7 @@ to an iteration construct, whereas the C<$> sigil indicates only one value.
     my $a = (1, 2, 3);
     for $a { };         # 1 iteration
 
-Contrary to earlier versions of Perl 6, and to Perl 5, C<@>-sigiled variables
-do not flatten in list context:
+C<@>-sigiled variables do not flatten in list context:
 
     my @a = 1, 2, 3;
     my @b = @a, 4, 5;