docs: update 7-1-ap-overview.md

[habib424]

Drafted by Ship Ship 🚢 — confidence 🟢 high

What changed

Added a note in the Key Features section that credit entries now include a Payments tab, bringing them to feature parity with bills and customer credits for viewing payment history and reversing bank payments.

Source PRs

• axolotl#4232 — feat(GREEN-1447): Add payments tab to credit entries

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.