gh-101336: Add keep_alive keyword arg for asyncio create_server() (#112485)

Doc/library/asyncio-eventloop.rst

@@ -671,6 +671,7 @@ Creating network servers
                         flags=socket.AI_PASSIVE, \
                         sock=None, backlog=100, ssl=None, \
                         reuse_address=None, reuse_port=None, \
+                        keep_alive=None, \
                         ssl_handshake_timeout=None, \
                         ssl_shutdown_timeout=None, \
                         start_serving=True)
@@ -735,6 +736,13 @@ Creating network servers
      set this flag when being created. This option is not supported on
      Windows.
 
+   * *keep_alive* set to ``True`` keeps connections active by enabling the
+     periodic transmission of messages.
+
+   .. versionchanged:: 3.13
+
+      Added the *keep_alive* parameter.
+
    * *ssl_handshake_timeout* is (for a TLS server) the time in seconds to wait
      for the TLS handshake to complete before aborting the connection.
      ``60.0`` seconds if ``None`` (default).