add ruff.toml with default config plus numpy docstrings

[galenseilis]

• Adding a ruff.toml.
• The rule set can be changed, but for the moment I want with the default given in the Ruff documentation with one added difference.
• The added difference is setting Ruff to use NumPy's pydocstyle rather than Googles or PEP257.
  • Discussion here seems to support this choice of convention.

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After there are some agreed rules for Ruff, I will start making non-breaking formatting changes.

[galenseilis]

#217

[geraintpalmer]

Hi @galenseilis Can you explain a bit more about what this is please?

[galenseilis]

Hi @galenseilis Can you explain a bit more about what this is please?

Absolutely. Ruff is a linting and formatting tool. What the ruff.toml specifies is configuration for when the ruff tool is used within the directory of this Python project.

• Here is the general documentation for ruff.
• There is also this introduction post you can review.

If you agree that we can use Ruff for working with Ciw, then we can also review and revise the proposed config in this PR.

Let me know what you think.