Fix imports

Author: jspahrsummers

README.md

@@ -22,8 +22,8 @@ npm install @modelcontextprotocol/sdk
 ### Creating a Client
 
 ```typescript
-import { Client } from "@modelcontextprotocol/sdk/client";
-import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio";
+import { Client } from "@modelcontextprotocol/sdk/client/index.js";
+import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js";
 
 const transport = new StdioClientTransport({
   command: "path/to/server",
@@ -59,8 +59,8 @@ const resourceContent = await client.request(
 ### Creating a Server
 
 ```typescript
-import { Server } from "@modelcontextprotocol/sdk/server";
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio";
+import { Server } from "@modelcontextprotocol/sdk/server/index.js";
+import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
 
 const server = new Server({
   name: "example-server",