Merge pull request 0xPolygon#2704 from 0xPolygon/x402-routes

adds x402 routes

Author: arash009

mkdocs.yml

@@ -67,6 +67,10 @@ nav:
           - Stripe: pos/payments/onramps/onramps-stripe.md
         - Transfers: 
           - USDC: pos/payments/transfers/transfer-usdc.md
+        - x402:
+          - Overview: pos/payments/x402/overview.md
+          - Quickstart for Buyers: pos/payments/x402/buyers.md
+          - Quickstart for Sellers: pos/payments/x402/sellers.md
       - Node how-tos:
         - Prerequisites: pos/how-to/prerequisites.md
         - Sync node using snapshots: pos/how-to/snapshots.md