add the previous display_output hook as doc example

crates/nu-utils/src/sample_config/default_config.nu

@@ -294,7 +294,7 @@ $env.config = {
     env_change: {
       PWD: [{|before, after| null }] # run if the PWD environment is different since the last repl input
     }
-    display_output: { table } # run before the output of a command is drawn
+    display_output: { table } # run before the output of a command is drawn, example: `{ if (term size).columns >= 100 { table -e } else { table } }`
     command_not_found: { null } # return an error message when a command is not found
   }