2023-03-27 — Add Handle Amendment endpoint

The Handle Amendment endpoint directs Bold Checkout to recalculate the outstanding balance of the order compared to what was authorized in the Pre-Process Order endpoint and attempt to add an additional payment if required.

This endpoint is intended to be used with the Pre-Process Order endpoint in scenarios where additional changes are made to the order after the initial authorization for payment is acquired but before the order is submitted for processing, such as when upselling the customer after checkout.