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

@@ -93,7 +93,7 @@ npx graphclient-x402 "{ pairs(first: 5) { id } }" \
   --chain base
 ```
 
-**Option B: Programmatic**
+#### Option B: Programmatic
 
 ```typescript
 import { createGraphQuery } from '@graphprotocol/client-x402'