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 = '''