add example using peer keepalive vrf and delay restore (ansible#41111)

* add example using peer keepalive vrf and delay restore

<!--- Your description here -->
add example using peer keepalive vrf and delay restore
+label: docsite_pr
+label: issue ansible/community#311

* Update nxos_vpc.py

update task name to include "existing"

lib/ansible/modules/network/nxos/nxos_vpc.py

@@ -101,6 +101,18 @@
     pkl_src: 10.1.100.2
     pkl_dest: 192.168.100.4
     auto_recovery: true
+
+- name: Configure VPC with delay restore and existing keepalive VRF
+  nxos_vpc:
+    domain: 10
+    role_priority: 28672
+    system_priority: 2000
+    delay_restore: 180
+    peer_gw: true
+    pkl_src: 1.1.1.2
+    pkl_dest: 1.1.1.1
+    pkl_vrf: vpckeepalive
+    auto_recovery: true
 '''
 
 RETURN = '''