fix(ip): Complete more variations of subcommands

Author: yedayak

completions/ip

@@ -275,7 +275,7 @@ _comp_cmd_ip()
             esac
             ;;
 
-        neigh)
+        n | neigh | neighbor | neighbour)
             case $subcmd in
                 add | del | change | replace)
                     # TODO
@@ -306,7 +306,7 @@ _comp_cmd_ip()
             esac
             ;;
 
-        tunnel)
+        tun | tunnel)
             case $subcmd in
                 show) ;;
 
@@ -369,7 +369,7 @@ _comp_cmd_ip()
             esac
             ;;
 
-        netns)
+        net | netns)
             case $subcmd in
                 list | monitor) ;;