Refactor GraphQL endpoint options for clarity

[zambianchi]

This PR updates the documentation and code examples for NitroAppOptions to align with the breaking changes introduced in Hot Chocolate v16.
With the introduction of new overloads in v16 (such as the distinction between different configuration contexts), the compiler may fail to resolve the correct method.

Key Changes

• Explicit Type Declaration: Updated examples to use explicit typing in lambda expressions (e.g., (NitroAppOptions option) => ...) to prevent AmbiguousMatchException or compilation errors.

• Property Mapping: Refined the usage of option.Enable and option.ServeMode to reflect the latest recommended defaults for development and testing environments

Before (v15 and below):

.WithOptions(option => {
    option.Title = "My API";
})

After (v16 - Recommended):

.WithOptions((NitroAppOptions option) => {
    option.Title = "My API";
})

[CLAassistant]

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