Clarify IO::CatHandle.words/.lines

Even if :$close is false, the handle switching mechanism will still close
consumed handles. Otherwise, we'd hit the open files limit fairly quickly.

doc/Type/IO/CatHandle.pod6

@@ -306,6 +306,9 @@ IO::CatHandle.new($f1, $f2).lines.perl.say;
 # OUTPUT: «("foo", "bar", "meow").Seq␤»
 =end code
 
+Note: if C<:$close> is C<False>, fully-consumed handles are B<still> going
+to be closed.
+
 =head2 method lock
 
 Defined as:
@@ -736,6 +739,9 @@ IO::CatHandle.new($f1, $f2).words.perl.say;
 # OUTPUT: «("foo", "bar", "meow").Seq␤»
 =end code
 
+Note: if C<:$close> is C<False>, fully-consumed handles are B<still> going
+to be closed.
+
 =head1 NYI Methods
 
 The L<IO::CatHandle> type overrides these methods to throw C<X::NYI>