copies-tests: add a summary of all cases created in test-copies-chain-merge.t
This helps to keep track of existing branch when adding new cases.
Differential Revision: https://phab.mercurial-scm.org/D9588
[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true