asyncio doc: add a "Coroutines and protocols" section
diff --git a/Doc/library/asyncio-stream.rst b/Doc/library/asyncio-stream.rst
index 0772516..f2a9f12 100644
--- a/Doc/library/asyncio-stream.rst
+++ b/Doc/library/asyncio-stream.rst
@@ -1,5 +1,7 @@
 .. currentmodule:: asyncio
 
+.. _streams:
+
 ++++++++++++++++++++++++
 Streams (high-level API)
 ++++++++++++++++++++++++