chore: complete the email signuture

src/app.module.ts

@@ -21,6 +21,7 @@ import { EmailModule } from "./modules/email/email.module";
 import { MailServerModule } from "./modules/mail-server/mail-server.module";
 import { MailboxModule } from "./modules/mailbox/mailbox.module";
 import { QuotaSyncModule } from "./modules/quota-sync/quota-sync.module";
+import { EmailSignaturesModule } from "./modules/signatures/email-signatures.module";
 import { UsersModule } from "./modules/users/users.module";
 import { UtilsModule } from "./modules/utils/utils.module";
 
@@ -42,6 +43,7 @@ import { UtilsModule } from "./modules/utils/utils.module";
     MailboxModule,
     MailServerModule,
     QuotaSyncModule,
+    EmailSignaturesModule,
   ],
 })
 export class AppModule implements NestModule {