examples: include a sample of how to use black with fix
It's commented out for now since my patch hasn't landed, but we can
uncomment it when that lands.
Differential Revision: https://phab.mercurial-scm.org/D6974
[fix]
clang-format:command = clang-format --style file -i
clang-format:pattern = (**.c or **.cc or **.h) and not "listfile:contrib/clang-format-ignorelist"
rustfmt:command = rustfmt {rootpath}
rustfmt:pattern = set:**.rs
# We use black, but currently with https://github.com/psf/black/pull/826 applied.
# black:command = black --skip-string-normalization
# black:pattern = set:**.py - hgext/fsmonitor/pywatchman/** - mercurial/thirdparty/** - "contrib/python-zstandard/**"