Update index.ts to expose SimpleWalletClient object

The SimpleWalletClient object is needed by developers creating Web3 apps that interact with the user's wallet.  For example:

        const config: StoryConfig = {
            chainId: await this.getCurrentChainId(), // Get the current chain ID from MetaMask
            transport: http(RPCProviderUrl), // Using MetaMask's provider
            wallet: this.walletClient as SimpleWalletClient
        };


This is so they can interact with the user's wallet for doing important operations on the Story Protocol blockchain, like signing payloads or paying for transactions.

packages/core-sdk/src/index.ts

@@ -143,3 +143,5 @@ export type {
 
 export { getPermissionSignature, getSignature } from "./utils/sign";
 export { convertCIDtoHashIPFS, convertHashIPFStoCID } from "./utils/ipfs";
+
+export type { SimpleWalletClient } from "../src/abi/generated.js";