Adjust man page for new functionality

Signed-off-by: Tony Zelenoff <antonz@parallels.com>

man/man8/ip-neighbour.8

@@ -24,7 +24,7 @@ ip-neighbour \- neighbour/arp tables management.
 .IR DEV " ]"
 
 .ti -8
-.BR "ip neigh" " { " show " | " flush " } [ " to
+.BR "ip neigh" " { " show " | " flush " } [ " proxy " ] [ " to
 .IR PREFIX " ] [ "
 .B  dev
 .IR DEV " ] [ "
@@ -132,6 +132,10 @@ the prefix selecting the neighbours to list.
 .BI dev " NAME"
 only list the neighbours attached to this device.
 
+.TP
+.BI proxy
+list neighbour proxies.
+
 .TP
 .B unused
 only list neighbours which are not currently in use.