Add option to ignore files

[santisoler]

Description of the desired feature:

Would be nice if we can include a list of files in the pyproject.toml that we don't want to be checked or modified by burocrata. The syntax could be similar to what isort does with skip, flake8 with exclude, and ruff with exclude.

It would be nice if we can list files and/or globs. For example:

[tool.burocrata]
notice = '''
# Copyright (c) YYYY Name of Developer.
# Distributed under the terms of the BSD 3-Clause License.
# SPDX-License-Identifier: BSD-3-Clause'''
exclude = ["foo/bar.py", "lorem/*.py"]

This idea originated in https://github.com/orgs/fatiando/discussions/139#discussioncomment-8647144

Are you willing to help implement and maintain this feature?

That will be fun!