feat(ESModules): importing for esm modules (#3998)

* fix: importing for esm modules

* style: use single quotes

* refactor: remove 'use strict'

esm/discord.mjs

@@ -0,0 +1,89 @@
+import Discord from '../src/index.js';
+
+export default Discord;
+
+export const {
+  BaseClient,
+  Client,
+  Shard,
+  ShardClientUtil,
+  ShardingManager,
+  WebhookClient,
+  ActivityFlags,
+  BitField,
+  Collection,
+  Constants,
+  DataResolver,
+  BaseManager,
+  DiscordAPIError,
+  HTTPError,
+  MessageFlags,
+  Intents,
+  Permissions,
+  Speaking,
+  Snowflake,
+  SnowflakeUtil,
+  Structures,
+  SystemChannelFlags,
+  Util,
+  version,
+  ChannelManager,
+  GuildChannelManager,
+  GuildEmojiManager,
+  GuildEmojiRoleManager,
+  GuildMemberManager,
+  GuildMemberRoleManager,
+  GuildManager,
+  ReactionUserManager,
+  MessageManager,
+  PresenceManager,
+  RoleManager,
+  UserManager,
+  discordSort,
+  escapeMarkdown,
+  fetchRecommendedShards,
+  resolveColor,
+  resolveString,
+  splitMessage,
+  Base,
+  Activity,
+  APIMessage,
+  CategoryChannel,
+  Channel,
+  ClientApplication,
+  ClientUser,
+  Collector,
+  DMChannel,
+  Emoji,
+  Guild,
+  GuildAuditLogs,
+  GuildChannel,
+  GuildEmoji,
+  GuildMember,
+  Integration,
+  Invite,
+  Message,
+  MessageAttachment,
+  MessageCollector,
+  MessageEmbed,
+  MessageMentions,
+  MessageReaction,
+  NewsChannel,
+  PermissionOverwrites,
+  Presence,
+  ClientPresence,
+  ReactionCollector,
+  ReactionEmoji,
+  RichPresenceAssets,
+  Role,
+  StoreChannel,
+  Team,
+  TeamMember,
+  TextChannel,
+  User,
+  VoiceChannel,
+  VoiceRegion,
+  VoiceState,
+  Webhook,
+  WebSocket
+} = Discord;