Added support arrow function

[tabuna]

This sentence modifies the return value for generator methods.

Before

Breadcrumbs::for('home', function ($trail) {
    $trail->parent('home');
    $trail->push('About');
});

After

Breadcrumbs::for('home', function ($trail) {
    $trail->parent('home')->push('About');
});

This small change does not affect backward compatibility. At the same time, it supports arrow functions:

Breadcrumbs::for('home', fn ($trail) =>
    $trail->parent('home')->push('About')
);