docs: Add description for gi_suspended attribute

Author: codenamenam

Doc/library/inspect.rst

@@ -253,6 +253,9 @@ attributes (see :ref:`import-mod-attrs` for module attributes):
 +-----------------+-------------------+---------------------------+
 |                 | gi_running        | is the generator running? |
 +-----------------+-------------------+---------------------------+
+|                 | gi_suspended      | is the generator suspended|
+|                 |                   | ?                         |
++-----------------+-------------------+---------------------------+
 |                 | gi_code           | code                      |
 +-----------------+-------------------+---------------------------+
 |                 | gi_yieldfrom      | object being iterated by  |