added depreciated flag (#555)

Author: soheimam

docs/onchainkit/checkout/checkout.mdx

@@ -3,7 +3,6 @@ title: <Checkout /> · OnchainKit
 sidebarTitle: <Checkout />
 description: One-click checkout for onchain commerce
 ---
-
 import { Danger } from "/snippets/danger.mdx";
 
 The `Checkout` component provides a one-click checkout experience for onchain commerce - all for free.

docs/onchainkit/latest/components/checkout/checkout.mdx

@@ -4,6 +4,10 @@ title: "Checkout"
 
 import { Danger } from "/snippets/danger.mdx";
 
+<Warning>
+This component is deprecated. Please consider using [Base Pay](/base-account/guides/accept-payments).
+</Warning>
+
 The `Checkout` component provides a one-click checkout experience for onchain commerce - all for free.
 
 Our all-in-one solution simplifies payment processing for onchain developers, removing complex integrations, high fees, and onboarding friction. Whether you're selling digital goods, services, or in-game items, this tool is for you.