Improve migration document (#16072)
## Summary
This PR improves the migration document based on recent feedback.
[Rendered
version](https://github.com/astral-sh/ruff/blob/dhruv/migration/docs/editors/migration.md)
### Preview
<img width="1897" alt="Screenshot 2025-02-10 at 2 52 31 PM"
src="https://github.com/user-attachments/assets/596a3217-6598-4274-ab49-a89b9cb60fe0"
/>
