docs: Update index.md example to use stateless HTTP with JSON

Author: domdomegg

docs/index.md

@@ -17,7 +17,7 @@ Here's a simple MCP server that exposes a tool, resource, and prompt:
 ```python title="server.py"
 from mcp.server.fastmcp import FastMCP
 
-mcp = FastMCP("Test Server")
+mcp = FastMCP("Test Server", stateless_http=True, json_response=True)
 
 
 @mcp.tool()
@@ -36,6 +36,10 @@ def get_greeting(name: str) -> str:
 def greet_user(name: str, style: str = "friendly") -> str:
     """Generate a greeting prompt"""
     return f"Write a {style} greeting for someone named {name}."
+
+
+if __name__ == "__main__":
+    mcp.run(transport="streamable-http")
 ```
 
 Test it with the [MCP Inspector](https://github.com/modelcontextprotocol/inspector):