[Erw-devel] docs fix - button inhibit example

[erw-devel]

Hi,
A quick fix to the docs in ERW 1.0.9 (& devel). The section on the The 
Button Inhibition Hook has an example that needs changing from

$D["book"]["inhibit"]["list"]["new"] = true;
$D["book"]["inhibit"]["list"]["modify"] = true;
$D["book"]["inhibit"]["list"]["delete"] = true;

to

$D["book"]["inhibit"]["main"]["new"] = true;
$D["book"]["inhibit"]["main"]["modify"] = true;
$D["book"]["inhibit"]["main"]["delete"] = true;

Found out this via the examples/lsr/custom/ files (thanks for the examples!)

Cheers,
Jason.