docs: update 5-6-multi-entity-ledger.md

[habib424]

Drafted by Ship Ship 🚢 — confidence 🟡 medium

What changed

Added a short paragraph under "Intercompany Transactions" noting that supplier bills can now be settled against any payment-enabled ledger account (e.g., an intercompany loan, due-to/due-from, or clearing account), not just a bank account, with settlement in the bill's currency and no FX applied.

Source PRs

• light#7379 — feat(GREEN-1056): pay AP bills via any ledger account (intercompany loan etc.)

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.