docs: Suggest peer limit 1 instead of 2

docs/site-example/site.conf

@@ -94,7 +94,7 @@
     groups = {
       backbone = {
         -- Limit number of connected peers to reduce bandwidth.
-        limit = 2,
+        limit = 1,
 
         -- List of peers.
         peers = {

docs/user/site.rst

@@ -141,7 +141,7 @@ fastd_mesh_vpn
         mtu = 1426,
         groups = {
           backbone = {
-            limit = 2,
+            limit = 1,
             peers = {
               peer1 = {
                 key = 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX',