docs(MessageManager): add clarification to fetch messages (#9222)

* docs(MessageManager): add clarification to fetch messages

[Discord's documentation](https://discord.com/developers/docs/resources/channel#get-channel-messages) mentions that you can only use before, after or around. This is not mentioned in D.JS documentation, and after some time trying to figure out why I was getting more messages than I should, decided to read the documentation.

* docs(MessageManager): remove mutually exclusive description

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Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

packages/discord.js/src/managers/MessageManager.js

@@ -49,6 +49,7 @@ class MessageManager extends CachedManager {
 
   /**
    * Options used to fetch multiple messages.
+   * <info>The `before`, `after`, and `around` parameters are mutually exclusive.</info>
    * @typedef {Object} FetchMessagesOptions
    * @property {number} [limit] The maximum number of messages to return
    * @property {Snowflake} [before] Consider only messages before this id