Docs updates for E/A#94601 QuickBooks Online Items import setting

[MelvinBot]

Summary

PR #94601 adds a QuickBooks Online → Import → Items toggle in New Expensify. The Configure QuickBooks Online help article listed every other QBO import option (Chart of accounts, Classes, Customers/Projects, Locations, Taxes) but not Items, so this PR adds it.

Change

• Added an Items bullet to the Step 1: Configure Import Settings list, placed between Locations and Taxes to match the order shown in the QBO Import menu.

Verification against the UI / PR

• Toggle label verified against the new copy added in the source PR: items: 'Items' (src/languages/en.ts).
• Menu placement (Locations → Items → Taxes) verified against QuickbooksImportPage.tsx in the source PR.
• The Items toggle is a simple import on/off toggle (mirrors the QuickBooks Desktop Items implementation), so the doc entry is kept to a single import line rather than describing tag/report-field options (QBO Items has no such choice).

⚠️ Backend dependency: The source PR notes it adds App-side scaffolding only — the UpdateQuickbooksOnlineSyncItems backend command and the QBO sync that actually pulls Items must exist for the toggle to function end-to-end. Please confirm the feature is live before this doc is published, and adjust the wording if Items are imported in a specific way (e.g., as tags) once backend behavior is finalized.

@bernhardoj, please review the files changed and confirm they reflect the current behavior. Then mark this PR Ready for review.