fix: wrong return annotation

[Mohammad-Alavi]

Summary

The incorrect annotation is causing confusion in static analysis.
The create method actually returns \Spatie\Fractal\Fractal, not \Spatie\Fractalistic\Fractal. When Fractal::create is called, it invokes the parent (Fractalistic) create method using parent::create. This parent method, in turn, uses the new static keyword to return an instance of the subclass when called from that subclass. Therefore, the return type of Fractal::create is actually Fractal, not Fractalistic.
So, by changing the annotated return type to @return static, we can easily extend \Spatie\Fractal\Fractal and the return type problem will be solved.

Problem

Consider this example: You've created a macro named ok on Fractal. However, your IDE complains that the ok method doesn't exist on Fractalistic. The issue lies in the @return annotation, which incorrectly indicates that create returns Fractalistic instead of Fractal. By correcting this annotation, static analyzers will recognize the macro on Fractal.

[freekmurze]

Thanks!