code: def relative_to_contrib(diff, project):
      
      path = pathlib.Path(diff.b_path)
      contrib_path = project.contrib_module_path
      return path.relative_to(contrib_path)
docs: Compute relative path of changed file to contrib dir
  
      Args:
          diff (git.diff.Diff): file diff
          project (Project): project
  
      Returns:
          Path