chore: hide node.perf configs

these configs are rarely needed by regular users
and if they are to be changed, it should be done by
someone who really understands what they mean

apps/emqx/src/emqx_schema.erl

@@ -1492,7 +1492,7 @@ fields("broker") ->
         {"perf",
             sc(
                 ref("broker_perf"),
-                #{}
+                #{hidden => true}
             )},
         {"shared_subscription_group",
             sc(