message: Add descriptions for ApplicationCommandTypes
diff: export enum ApplicationCommandTypes {
  + /** A text-based command that shows up when a user types `/` */
  ChatInput = 1,
  + /** A UI-based command that shows up when you right click or tap on a user */
  User,
  + /** A UI-based command that shows up when you right click or tap on a message */
  Message,
  }
  