Update README.md (#1066)

Use simple Note and Warning due to lack of support in vercel templates

README.md

@@ -118,10 +118,10 @@ pnpm i
 
 Currently, Saleor Storefront supports payments via the [Saleor Adyen App](https://docs.saleor.io/docs/3.x/developer/app-store/apps/adyen). To install and configure the payment app go to the "Apps" section in the Saleor Dashboard (App Store is only available in Saleor Cloud).
 
-> [!WARNING]
+> WARNING:
 > To configure the Adyen App, you must have an account with [Adyen](https://www.adyen.com/).
 
-> [!NOTE]
+> NOTE:
 > Saleor Stripe App integration is a work in progress.
 
 ## Development
@@ -134,7 +134,7 @@ pnpm dev
 
 The app is now running at `http://localhost:3000`.
 
-> [!NOTE]
+> NOTE:
 > Saleor Storefront is a Next.js app. In case you are not familiar with Next.js, we recommend you to read the [Next.js documentation](https://nextjs.org/docs) (make sure you've selected "Using App Router" in the sidebar).
 
 #### GraphQL queries and mutations: