bpo-33985: Implement ContextVar.name attribute. (GH-7980)

(cherry picked from commit 41cb0baea96a80360971908a0bd79d9d40dd5e44)

Co-authored-by: Yury Selivanov <yury@magic.io>
diff --git a/Doc/library/contextvars.rst b/Doc/library/contextvars.rst
index 9c7ea2b..8805661 100644
--- a/Doc/library/contextvars.rst
+++ b/Doc/library/contextvars.rst
@@ -48,6 +48,8 @@
 
       The name of the variable.  This is a read-only property.
 
+      .. versionadded:: 3.7.1
+
    .. method:: get([default])
 
       Return a value for the context variable for the current context.