docs: fix guildChannel#toString() example (#2203)

* fix the docs

* don't log something what you don't log

src/structures/GuildChannel.js

@@ -404,10 +404,10 @@ class GuildChannel extends Channel {
    * When concatenated with a string, this automatically returns the channel's mention instead of the Channel object.
    * @returns {string}
    * @example
-   * // Outputs: Hello from #general
+   * // Logs: Hello from <#123456789012345678>
    * console.log(`Hello from ${channel}`);
    * @example
-   * // Outputs: Hello from #general
+   * // Logs: Hello from <#123456789012345678>
    * console.log('Hello from ' + channel);
    */
   toString() {