feat: add payment module and factory

src/configs/zarinpal.config.ts

@@ -0,0 +1,20 @@
+import { ConfigService } from "@nestjs/config";
+
+export function zarinpalConfig() {
+  return {
+    inject: [ConfigService],
+    useFactory: (configService: ConfigService) => ({
+      merchantId: configService.getOrThrow<string>("ZARINPAL_MERCHANT_ID"),
+      gatewayApiUrl: configService.getOrThrow<string>("ZARINPAL_API_URL"),
+      callBackUrl: configService.getOrThrow<string>("CALLBACK_URL"),
+      ipgType: configService.getOrThrow<string>("IPG_TYPE"),
+    }),
+  };
+}
+
+export interface IZarinpalConfig {
+  merchantId: string;
+  gatewayApiUrl: string;
+  callBackUrl: string;
+  ipgType: string;
+}