fix: sync payment_started_at (#103)

We missed the field in the schema mapping

Author: kevcodez

packages/orb-sync-lib/src/schemas/invoice.ts

@@ -33,6 +33,7 @@ export const invoiceSchema: JsonSchema = {
     minimum_amount: { type: 'number' },
     paid_at: { type: 'string' },
     payment_failed_at: { type: 'string' },
+    payment_started_at: { type: 'string' },
     scheduled_issue_at: { type: 'string' },
     shipping_address: { type: 'object' },
     status: { type: 'string' },