message: Document json flag of gp top cmd
diff: @@ -258,8 +258,10 @@ gp ports await 3000 && gp preview $(gp url 3000)/my/path/index.html
  ## top
  -Displays the used and available workspace CPU and memory.
  +Displays the current workspace's class info along with the used and available CPU and memory.
  ```sh
  gp top
  ```
  +
  +You can also use `gp top --json` to get output in JSON format if you want to access them.
  