enable auto-fix as feature/flag

[Borda]

trafficstars

When used together with pre-commit inspired by Black or Ruff, it would be great if this lint doe example could carry some safe/trivial fixes:

• trailing whitespace
• No newline at end of file
• horizontal-tab (maybe)

otherwise, when you want to apply lint to a small/existing project, it could be quite time-consuming; see for example https://github.com/sphinx-gallery/sphinx-gallery/pull/1266