docs: update README

README.md

@@ -30,8 +30,8 @@ import { createClient, createRpcClient } from "@coinbasejs/onchain";
 
 // 2. Create an RPC client
 const rpcClient = createRpcClient({
-  url: RPC_URL,
   apiKey: "API_KEY",
+  network: "base",
 });
 
 // 3. Send request
@@ -47,19 +47,20 @@ const response = await rpcClient.request({
 
 // For convenience, you can also create a higher-level client
 const client = createClient({
-  apiKey: '<API_KEY>',
+  apiKey: "API_KEY",
+  network: "base",
 });
 
 // Send request
-const balances = await client.listBalances([{
+const balances = await client.getBalances([{
   address: "0x5ff137d4b0fdcd49dca30c7cf57e578a026d2789",
   pageSize: 1,
 }]);
 ```
 
 ## Documentation
 
-TODO
+Read the [documentation](https://coinbasejs.com/) to learn more about coinbasejs.
 
 ## License