proposal: provide file-level feedback

[CarlJi]

The current feedback from Reviewbot is only at the contextual level of the diff code. This creates a possibility where, in order to fix one issue, a new diff is introduced, leading to new problems and making the PR author feel like the issues are never-ending.

Therefore, the plan is to provide file-level error feedback that can be enabled through configuration when needed.

The benefit of this approach is that it allows for the prompt resolution of lingering issues in the repository.

Furthermore, we can even provide repository-level error feedback in the future.

[CarlJi]

For file or repository-level issue feedback, since it is not within the context of a diff, GitHub likely does not support commenting directly within the code. Therefore, it could be considered to provide the feedback in the form of issue comments.