feat(openapi): automatically generate OpenAPI spec from code (#318)

Co-authored-by: bernard eugine <bernard.eugine@bernard.eugine-MacBookPro>
Co-authored-by: Sanchith Hegde <sanchith.hegde@juspay.in>

crates/router/src/openapi.rs

@@ -0,0 +1,67 @@
+#[derive(utoipa::OpenApi)]
+#[openapi(
+    info(
+        title = "Juspay Router - API Documentation",
+        contact(
+            name = "Juspay Support",
+            url = "https://juspay.io",
+            email = "support@juspay.in"
+        ),
+        // terms_of_service = "https://www.juspay.io/terms",
+        description = r#"
+## Get started
+
+Juspay Router provides a collection of APIs that enable you to process and manage payments.
+Our APIs accept and return JSON in the HTTP body, and return standard HTTP response codes.
+
+You can consume the APIs directly using your favorite HTTP/REST library.
+
+We have a testing environment referred to "sandbox", which you can setup to test API calls without
+affecting production data.
+
+### Base URLs
+
+Use the following base URLs when making requests to the APIs:
+
+| Environment   |  Base URL                                            |
+|---------------|------------------------------------------------------|
+| Sandbox       | <https://sandbox-router.juspay.io>                   |
+| Production    | <https://router.juspay.io>                           |
+
+## Authentication
+
+When you sign up on our [dashboard](https://orca-dahboard.netlify.app) and create a merchant
+account, you are given a secret key (also referred as api-key).
+You may authenticate all API requests with Juspay server by providing the appropriate key in the
+request Authorization header.
+
+Never share your secret api keys. Keep them guarded and secure.
+"#,
+    ),
+    servers(
+        (url = "https://sandbox-router.juspay.io", description = "Sandbox Environment"),
+        (url = "https://router.juspay.io", description = "Production Environment")
+    ),
+    paths(
+        crate::routes::refunds::refunds_create,
+        crate::routes::admin::merchant_account_create
+    ),
+    components(schemas(
+        crate::types::api::refunds::RefundRequest,
+        crate::types::api::refunds::RefundType,
+        crate::types::api::refunds::RefundResponse,
+        crate::types::api::refunds::RefundStatus,
+        crate::types::api::admin::CreateMerchantAccount,
+        crate::types::api::admin::CustomRoutingRules,
+        api_models::enums::RoutingAlgorithm,
+        api_models::enums::PaymentMethodType,
+        api_models::enums::PaymentMethodSubType,
+        api_models::enums::Currency,
+        api_models::payments::AddressDetails,
+        crate::types::api::admin::MerchantAccountResponse,
+        crate::types::api::admin::MerchantConnectorId,
+        crate::types::api::admin::MerchantDetails,
+        crate::types::api::admin::WebhookDetails,
+    ))
+)]
+pub struct ApiDoc;