[FR]: Add support for custom file name

[ricardodalarme]

Is there an existing issue for this?

• [X] I have searched the existing issues

Describe the problem

I'd like to customize the output file name, my project is organized in:

- /constants
  - app_images
  - app_colors
  - app_configs

And it would be really nice if I could use this package keeping this pattern.

Describe the solution

Add an option in the pubspec.yaml to edit the file name and also remove the .gen (plssss)

Additional context

No response

Code of Conduct

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