[Feature request] Preserve folder structure

[athewsey]

When applying textractor to a local folder or S3 prefix with an inner folder structure, it would be really useful if output files were also mapped to the same folder structure - rather than flattened out by filename only.

For example processing a parent folder containing invoices/ABC123.pdf and purchase-orders/DEF456.pdf currently seems to generate ABC123-response.json and DEF456-response.json - which then need to be mapped back to their categories afterwards.