fix: correct typo in backend wallets documentation

Author: d4mr

apps/portal/src/app/engine/features/backend-wallets/page.mdx

@@ -22,7 +22,7 @@ Smart backend wallets are the recommended way to perform blockchain operations w
 Smart backend wallets inherit smart account benefits and offer several advantages over traditional EOAs:
 
 - **Gas Management**: Built-in paymaster eliminates the need to maintain gas tokens. This means you never need to hold crypto or top up for gas.
-- **Better Nonce Management**: Smart accounts use multi-dimensnal nonces, which are more efficient than EOAs.
+- **Better Nonce Management**: Smart accounts use multi-dimensional nonces, which are more efficient than EOAs.
 - **Simple Integration**: Works with all existing Engine endpoints without any code changes.
 
 ### How it works