types(CategoryChannel): Ensure parent and parentId are null (#9327)

types: ensure categories' parents are `null`

packages/discord.js/src/structures/CategoryChannel.js

@@ -8,9 +8,22 @@ const CategoryChannelChildManager = require('../managers/CategoryChannelChildMan
  * @extends {GuildChannel}
  */
 class CategoryChannel extends GuildChannel {
+  /**
+   * The id of the parent of this channel.
+   * @name CategoryChannel#parentId
+   * @type {null}
+   */
+
+  /**
+   * The parent of this channel.
+   * @name CategoryChannel#parent
+   * @type {null}
+   * @readonly
+   */
+
   /**
    * Sets the category parent of this channel.
-   * <warn>It is not currently possible to set the parent of a CategoryChannel.</warn>
+   * <warn>It is not possible to set the parent of a CategoryChannel.</warn>
    * @method setParent
    * @memberof CategoryChannel
    * @instance

packages/discord.js/typings/index.d.ts

@@ -892,6 +892,8 @@ export type CategoryChannelType = Exclude<
 export class CategoryChannel extends GuildChannel {
   public get children(): CategoryChannelChildManager;
   public type: ChannelType.GuildCategory;
+  public get parent(): null;
+  public parentId: null;
 }
 
 export type CategoryChannelResolvable = Snowflake | CategoryChannel;