Document Sanctum API token integration for Laravel 12

[titusfrezer]

Added instructions for integrating Laravel Sanctum's API token authentication with Tenancy for Laravel in Laravel 12, including middleware configuration.

[stancl]

Hi, thanks for the PR.

I am not sure why this would be necessary though considering middleware priority is already configured in TenancyServiceProvider.

[titusfrezer]

I see, what I faced was I just created a custom middleware which wraps the InitializeTenancyBySubDomain; so I got null when accessing $request->user(); so don't you think it is worth it mentioning the priority of the middleware in the TenancyServiceProvider.

Thank you for the clarification.