Fix and improve `asyncio.run()` docs (GH-16403) (GH-16504)

(cherry picked from commit e407013089259e4c0b271703e1975bbcd578a2d5)

Co-authored-by: Kyle Stanley <aeros167@gmail.com>
diff --git a/Doc/glossary.rst b/Doc/glossary.rst
index e601e8b..9ce0357 100644
--- a/Doc/glossary.rst
+++ b/Doc/glossary.rst
@@ -247,7 +247,7 @@
       Fortran contiguous arrays, the first index varies the fastest.
 
    coroutine
-      Coroutines is a more generalized form of subroutines. Subroutines are
+      Coroutines are a more generalized form of subroutines. Subroutines are
       entered at one point and exited at another point.  Coroutines can be
       entered, exited, and resumed at many different points.  They can be
       implemented with the :keyword:`async def` statement.  See also