Attach documents to expenses (#64)

* Upload documents to receipts

* Improve documents

* Make the feature opt-in

* Fix file name issue

prisma/migrations/20240128192510_update_document_urls/migration.sql

@@ -0,0 +1,9 @@
+/*
+  Warnings:
+
+  - The `documentUrls` column on the `Expense` table would be dropped and recreated. This will lead to data loss if there is data in the column.
+
+*/
+-- AlterTable
+ALTER TABLE "Expense" DROP COLUMN "documentUrls",
+ADD COLUMN     "documentUrls" JSONB[] DEFAULT ARRAY[]::JSONB[];