small suggested change for examples in array docs

Most examples in the array documentation uses ARRAY[1,2,3] and similar.

http://www.postgresql.org/docs/9.0/interactive/functions-array.html

I think (actually I have experienced it, both in myself and others)
that this can be misleading in some cases.
For example:   array_upper(ARRAY[1,2,3,4], 1) => 4  : (is this '4' a
value or an index ?)
Something like ARRAY[10,20,30,40] would be a better choice.

Hernán