message: docs: fix the preview description
diff: @@ -173,7 +173,7 @@ Gets the process management settings of an App.
  | ------- | :--------------: | :------: | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
  | app | Number or String | Yes | The App ID. |
  | lang | String | | The localized language to retrieve the data in:<ul><li>`default`: retrieves the default names</li><li>`en`: retrieves the localized English names</li><li>`zh`: retrieves the localized Chinese names</li><li>`ja`: retrieves the localized Japanese names</li><li>`user`: retrieves the localized names, in the same language as the language setting set on the user used for the authentication.</li></ul>If ignored, the default names will be retrieved. |
  -| preview | Boolean | | A flag whether to get the customization settings for pre-live environment |
  +| preview | Boolean | | A flag whether to get the process management settings for pre-live environment |
  #### Returns
  