Add example of per-file-ignores in TOML to Readme

[tgross35]

Hello,

It took quite a few attempts to get the syntax right for configuring per-file-ignores in toml. Would you be able to add a quick example to the readme to help guide usage?

[tool.ruff]
per-file-ignores = [
    "**/__init__.py:F401",
    "directory/file.py:F401"
]

Side note - for toml configuration, could you consider allowing whitespace after the colon? "**/__init__.py: F401" is ever so slightly more readable, and matches the flake8 ini config a little bit closer.

Alternatively, it could be nice to be able to specify ignores in a more toml-y way

[tools.ruff.per-file-ignores]
"**/__init__.py" = ["F401",  "D100"]
"directory/file.py" = ["F401", "C409",  "B014"]

# or the other way around
[tools.ruff.per-file-ignores]
F401 = [
    "**/__init__.py",
    "directory/file.py"
]

[charliermarsh]

Good suggestions all around! I haven't changed the actual syntax (though I do like the suggestion)... though for now I went ahead and (1) supported whitespace as requested, and (2) added an example to the README.

As an aside, you should be able to do:

[tool.ruff]
per-file-ignores = [
    "__init__.py:F401",  # No need for ** -- this should match any file named `__init__.py`
    "directory/file.py:F401"
]

[tgross35]

Awesome! Thanks for the super quick update

[charliermarsh]

Always!

[charliermarsh]

(Going out in v0.0.86, which is building now.)