Source fixture: synthetic invoice excerpt for extractx_eval tests.

This is one already-scoped document excerpt. It is used as an extraction
case only; customer identity and downstream account correlation remain outside
extractx.

VENDOR NAME: Acme Supply Co.
VENDOR ID: VND-1001

Invoice INV-1001 was issued on April 13, 2020 for office supplies.
The subtotal amount is $700.00.
The applied tax rate is 2.25%.
The total amount due is $220.18.
Payment is due by April 28, 2020.
