docs: Add asyncio source code links (GH-16640)
diff --git a/Doc/library/asyncio.rst b/Doc/library/asyncio.rst
index 6990adb..94a8532 100644
--- a/Doc/library/asyncio.rst
+++ b/Doc/library/asyncio.rst
@@ -4,7 +4,7 @@
.. module:: asyncio
:synopsis: Asynchronous I/O.
---------------
+-------------------------------
.. sidebar:: Hello World!
@@ -91,3 +91,6 @@
asyncio-api-index.rst
asyncio-llapi-index.rst
asyncio-dev.rst
+
+.. note::
+ The source code for asyncio can be found in :source:`Lib/asyncio/`.