bpo-36921: Deprecate @coroutine for sake of async def (GH-13346)



The second attempt. Now deprecate `@coroutine` only, keep `yield from fut` as is.


https://bugs.python.org/issue36921
diff --git a/Doc/library/asyncio-task.rst b/Doc/library/asyncio-task.rst
index a1297f5..e7cf39b 100644
--- a/Doc/library/asyncio-task.rst
+++ b/Doc/library/asyncio-task.rst
@@ -916,12 +916,13 @@
         async def main():
             await old_style_coroutine()
 
-    This decorator is **deprecated** and is scheduled for removal in
-    Python 3.10.
-
     This decorator should not be used for :keyword:`async def`
     coroutines.
 
+    .. deprecated-removed:: 3.8 3.10
+
+       Use :keyword:`async def` instead.
+
 .. function:: iscoroutine(obj)
 
    Return ``True`` if *obj* is a :ref:`coroutine object <coroutine>`.