bpo-33649: Refresh asyncio docs landing page (GH-9322)

diff --git a/Doc/library/asyncio-future.rst b/Doc/library/asyncio-future.rst
index 2c41c1c..ff04339 100644
--- a/Doc/library/asyncio-future.rst
+++ b/Doc/library/asyncio-future.rst
@@ -1,6 +1,8 @@
 .. currentmodule:: asyncio
 
 
+.. _asyncio-futures:
+
 =======
 Futures
 =======