docs: stop presenting the in-memory client as the way to connect (#3443)

docs_src/legacy_clients/tutorial001_client.py

@@ -0,0 +1,23 @@
+import anyio
+
+from mcp import Client
+from mcp.client import ClientRequestContext
+from mcp.types import ElicitRequestParams, ElicitResult
+
+
+async def answer(context: ClientRequestContext, params: ElicitRequestParams) -> ElicitResult:
+    return ElicitResult(action="accept", content={"copies": 2})
+
+
+async def main() -> None:
+    async with (
+        Client("http://localhost:8000/mcp", mode="legacy", elicitation_callback=answer) as legacy,
+        Client("http://localhost:8000/mcp", elicitation_callback=answer) as modern,
+    ):
+        for client in (legacy, modern):
+            result = await client.call_tool("reserve", {"title": "Dune"})
+            print(client.protocol_version, result.structured_content)
+
+
+if __name__ == "__main__":
+    anyio.run(main)