fix: return the recipient as an array to match other formats from zapier (#971)

Return the recipient as an array to match the other formats for Zapier.
Otherwise, Zaps with the "DOCUMENT_OPENED" hooks won't work.

All the other webhooks return the "Recipient" field as an array.

packages/prisma/types/document-with-recipient.ts

@@ -5,6 +5,6 @@ export type DocumentWithRecipients = Document & {
 };
 
 export type DocumentWithRecipient = Document & {
-  Recipient: Recipient;
+  Recipient: Recipient[];
   documentData: DocumentData;
 };