chore: Add thread stuff

discordjs/discord.js#7539

guide/additional-info/changes-in-v14.md

@@ -172,6 +172,8 @@ The `message` and `interaction` events are now removed. Use `messageCreate` and
 
 `applicationCommandCreate`, `applicationCommandDelete` and `applicationCommandUpdate` have all been removed. Refer to [this pull request](https://github.com/discordjs/discord.js/pull/6492) for context.
 
+The `ThreadMembersUpdate` event now only emits the thread, the users who were added & and users who were removed respectively.
+
 ### GuildBanManager
 
 The `days` option when banning a user has been renamed to `deleteMessageDays` to be more aligned to the API name.
@@ -253,6 +255,8 @@ MessageComponents have been renamed as well. They no longer have the `Message` p
 
 The `PartialTypes` string array has been removed, instead use the `Partials` enum.
 
+In addition to this, there is now a new partial: `Partials.ThreadMember`.
+
 ### Permissions
 
 Thread permissions `USE_PUBLIC_THREADS` and `USE_PRIVATE_THREADS` have been removed as they are now deprecated in the API. Instead use the newer `*Threads` permission flags.