docs: update 11-6-stripe.md

[habib424]

Drafted by Ship Ship 🚢 — confidence 🟢 high

What changed

Added a note in the "Refund and chargeback handling" section clarifying that Stripe credit notes with line-level discounts and taxes are preserved during import, matching Stripe's final amounts. This documents a recent fix ensuring customer credits imported from discounted Stripe credit notes now show correct totals.

Source PRs

• light#6755 — Fix Stripe customer credit tax and discounts

How to use this PR

1. Review the diff against the existing article — focus on accuracy and customer voice.
2. Merge if it reads well. Edit and push to this branch if it needs adjustment.
3. Close without merging if the article doesn't actually need this update.

Once we have a track record of clean drafts, we'll graduate to auto-merge with a delay buffer. For now: human-in-the-loop.