Update website/src/pages/en/subgraphs/guides/x402-payments.mdx

Co-authored-by: Benoît Rouleau <1059139+benface@users.noreply.github.com>

Author: brandonleekramer

website/src/pages/en/subgraphs/guides/x402-payments.mdx

@@ -106,7 +106,7 @@ const query = createGraphQuery({
 const result = await query('{ pairs(first: 5) { id } }')
 ```
 
-**Option C: Typed SDK (full type safety)**
+#### Option C: Typed SDK (full type safety)
 
 ```bash
 npm install @graphprotocol/client-cli @graphprotocol/client-x402