[docs] add more complex examples with FFI, Native Assets, nativewrappers and freezed.

[munrocket]

Please add more examples, without it ecosystem in dart is poorer. It would be cool if a kid could figure out how to wrap tensorflow/graphics in dart.

[dart-github-bot]

Summary: User requests more complex Dart FFI, native assets, native wrappers, and Freezed examples in the documentation to improve ecosystem accessibility. More practical, real-world examples are needed.