Docs updates for E/A#90720 QBD company card export no longer auto-selects account or vendor

[MelvinBot]

Summary

Follow-up docs update for #90720, which stopped QuickBooks Desktop company card export from silently auto-selecting the first imported account and vendor when the export type changes.

The help article's Company Card Expenses section already listed the account/vendor fields without the old "first item (default)" wording, but it did not state that:

• No account or vendor is selected by default — the admin must explicitly choose one.
• Changing the export type clears any previously selected account and default vendor, so they must be re-selected.

This PR adds both clarifications to Configure-QuickBooks-Desktop.md.

Related

• App PR: Stop auto-selecting first account and vendor when changing QBD export type #90720
• App issue: [Due for payment 2026-06-17] QuickBooks Desktop: changing company-card export type silently picks first account and vendor #90721

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

[blimpich]

I feel like this is unnecessary