gh-84747: Add `async for` comment for StreamReader (#98633)

diff --git a/Doc/library/asyncio-stream.rst b/Doc/library/asyncio-stream.rst
index ce88d70d6607d9ae09c1d23efb1d5a615035e5bc..d87e3c042c997708d11466b4fa5ba3ba7d028869 100644 (file)
--- a/Doc/library/asyncio-stream.rst
+++ b/Doc/library/asyncio-stream.rst
@@ -183,7 +183,8 @@ StreamReader
 .. class:: StreamReader
 
    Represents a reader object that provides APIs to read data
-   from the IO stream.
+   from the IO stream. As an :term:`asynchronous iterable`, the
+   object supports the :keyword:`async for` statement.
 
    It is not recommended to instantiate *StreamReader* objects
    directly; use :func:`open_connection` and :func:`start_server`