FR: add Monad testnet support

[devasher-ca]

Describe the solution you would like
There is no support for monad testnet for now.

Additional context

import { alchemy, sepolia } from '@account-kit/infra'

export const config = createConfig(
  {
    transport: alchemy({ apiKey: "ALCHEMY_API_KEY" }), // TODO: add your Alchemy API key - https://dashboard.alchemy.com/accounts
    chain: sepolia,
    ssr: true, // more about ssr: https://accountkit.alchemy.com/react/ssr
    storage: cookieStorage, // more about persisting state with cookies: https://accountkit.alchemy.com/react/ssr#persisting-the-account-state
    enablePopupOauth: true, // must be set to "true" if you plan on using popup rather than redirect in the social login flow
  },
  uiConfig
);