fix: Update x420 references to x402 in documentation (#930)

* fix: Update x420 references to x402 in documentation

* fix: Correct x40 to x402 in Thirdweb Nexus description

Author: leandrogavidia

apps/web/content/guides/getstarted/intro-to-x402.mdx

@@ -137,8 +137,8 @@ support is added.
 | [ACK](#ack)                             | In PR                    | An agent payment protocol with x402 support                | [GitHub](https://github.com/agentcommercekit/ack)             |
 | [Crossmint](#crossmint)                 | In development           | Payments, wallets; agentic finance; not x402-specific      | [crossmint.com](https://www.crossmint.com/)                   |
 | [A2A x402 (Google)](#a2a-x402-google)   | In development           | Agent-to-Agent payments using google ai                    | [GitHub](https://github.com/google-agentic-commerce/a2a-x402) |
-| [Nexus (Thirdweb)](#nexus-thirdweb)     | In development           | x420 wrapper around API keys                               | [Nexus](https://nexus.thirdweb.com/)                          |
-| [x420scan](#x420scan)                   | N/A (Explorer)           | x420 ecosystem explorer (not an SDK)                       | [x420scan.com](https://x420scan.com/)                         |
+| [Nexus (Thirdweb)](#nexus-thirdweb)     | In development           | x402 wrapper around API keys                               | [Nexus](https://nexus.thirdweb.com/)                          |
+| [x402scan](#x402scan)                   | N/A (Explorer)           | x402 ecosystem explorer (not an SDK)                       | [x402scan.com](https://x402scan.com/)                         |
 | [Native Example](#native-example)       | Yes                      | Minimal example without dependencies                       | [Examples](https://github.com/Woody4618/x402-solana-examples) |
 
 ### Corbits
@@ -316,16 +316,16 @@ rails — including wallets, onramps, stablecoin orchestration, and more. Solana
 x402 support is currently in progress and is supposed to be finished by
 30.10.2025. Site: https://www.crossmint.com/
 
-### x420scan
+### x402scan
 
-Explorer for the x420 ecosystem that provides comprehensive stats, project
-listings, and analytics for x402/x420 implementations. Track transaction
+Explorer for the x402 ecosystem that provides comprehensive stats, project
+listings, and analytics for x402 implementations. Track transaction
 volumes, discover active merchants, and monitor the growth of payment-required
-endpoints across different networks. Site: https://x420scan.com/
+endpoints across different networks. Site: https://x402scan.com/
 
 ### Nexus (Thirdweb)
 
-Thirdweb Nexus develops a x420 wrapper around API keys (currently in
+Thirdweb Nexus develops a x402 wrapper around API keys (currently in
 development). Site: https://nexus.thirdweb.com/
 
 ## Native example