asyncio doc: more explicit doc for async()
The function schedules the execution of coroutines, it's not just a wrapper for
something.
diff --git a/Doc/library/asyncio-task.rst b/Doc/library/asyncio-task.rst
index 8c4d790..fa95ca9 100644
--- a/Doc/library/asyncio-task.rst
+++ b/Doc/library/asyncio-task.rst
@@ -478,7 +478,8 @@
.. function:: async(coro_or_future, \*, loop=None)
- Wrap a :ref:`coroutine object <coroutine>` in a future.
+ Schedule the execution of a :ref:`coroutine object <coroutine>`: wrap it in
+ a future. Return a :class:`Task` object.
If the argument is a :class:`Future`, it is returned directly.