Replace fake image in component x-typhoon-post

[happytodev]

Replace this

 <img class="h-40 w-full object-cover rounded-t-3xl object-center mb-6"
                src="{{ $post->main_image ? $post->main_image : 'https://dummyimage.com/720x400?dummy' }}"
                alt="content">

by something more convenient.

[happytodev]

The alternative image must still exist, but, Admin should be able to choose which default image he wants to display.
This can be achieved by a setting in config/typhoon.php