BaseClient: pass captureRejections option (#7288)

packages/discord.js/src/client/BaseClient.js

@@ -13,7 +13,7 @@ const Util = require('../util/Util');
  */
 class BaseClient extends EventEmitter {
   constructor(options = {}) {
-    super();
+    super({ captureRejections: true });
 
     if (typeof options !== 'object' || options === null) {
       throw new TypeError('INVALID_TYPE', 'options', 'object', true);

packages/discord.js/src/sharding/ShardClientUtil.js

@@ -210,6 +210,9 @@ class ShardClientUtil {
       error.stack = err.stack;
       /**
        * Emitted when the client encounters an error.
+       * <warn>Errors thrown within this event do not have a catch handler, it is
+       * recommended to not use async functions as `error` event handlers. See the
+       * [Node.js docs](https://nodejs.org/api/events.html#capture-rejections-of-promises) for details.</warn>
        * @event Client#error
        * @param {Error} error The error encountered
        */