Show the slurpy part of join in examples

[JJ]

The problem

Pointed out by @CIAvash in the perl 6 users list.

Suggestions

Add an example of this type of usage.

[CIAvash]

Maybe they should be combined into one example? or is it too much information?
join ', ', <a b c>, 'd', 'e' , 'f'

[JJ]

Not really. It's still in my editor, I'll add that.