Add Ruff documentation for Python linting and formatting

Added documentation for Ruff, a Python linter and formatter, including installation and usage instructions.

Author: jAniceto

programming-notes/python/ruff.md

@@ -0,0 +1,52 @@
+# Ruff - Python linter and code formatter
+
+## Installing
+
+Ruff can be invoked directly with `uvx`:
+
+```bash
+$ uvx ruff check   # Lint all files in the current directory.
+$ uvx ruff format  # Format all files in the current directory.
+```
+
+This runs `ruff` as a `uv` tool without installing it (it's installed in a temporary environment and deleted after use).
+
+Alternatively you can install with `uv` (recommended):
+
+To install Ruff globally.
+
+```bash
+$ uv tool install ruff@latest
+```
+
+## Usage
+
+### Lint
+
+```bash
+$ ruff check                  # Lint files in the current directory.
+$ ruff check --fix            # Lint files in the current directory and fix any fixable errors.
+$ ruff check --watch          # Lint files in the current directory and re-lint on change.
+$ ruff check path/to/code/    # Lint files in `path/to/code`.
+```
+
+For the full list of supported options, run `ruff check --help`.
+
+
+### Formatter
+
+```bash
+$ ruff format                   # Format all files in the current directory.
+$ ruff format path/to/code/     # Format all files in `path/to/code` (and any subdirectories).
+$ ruff format path/to/file.py   # Format a single file.
+```
+
+For the full list of supported options, run `ruff format --help`.
+
+
+### Sorting imports
+
+```bash
+$ ruff check --select I --fix
+$ ruff  format
+```