The docs currently state:

Scopes should always return a query builder instance

But in reality, the callScope method expects scopes to modify the provided Eloquent builder object. If you were to, in fact, return a new builder for some reason, it would break the addNewWheresWithinGroup functionality and potentially have other unexpected behavior (since this method is operating on the original query builder, not the one from the result of calling the scope).

This PR updates the docs to:

Scopes should always return the same query builder instance or void

And also changes one of the code samples to demonstrate the void return version of a named scope.