chore: overhaul readmes (#9277)

Co-authored-by: Souji <timoqueezle@gmail.com>
Co-authored-by: Noel <buechler.noel@outlook.com>

packages/core/README.md

@@ -83,7 +83,7 @@ const guild = await api.guilds.get('1234567891011');
 - [Website][website] ([source][website-source])
 - [Documentation][documentation]
 - [Guide][guide] ([source][guide-source])
-  See also the [Update Guide][guide-update], including updated and removed items in the library.
+  Also see the v13 to v14 [Update Guide][guide-update], which includes updated and removed items from the library.
 - [discord.js Discord server][discord]
 - [Discord API Discord server][discord-api]
 - [GitHub][source]
@@ -98,12 +98,11 @@ See [the contribution guide][contributing] if you'd like to submit a PR.
 
 ## Help
 
-If you don't understand something in the documentation, you are experiencing problems, or you just need a gentle
-nudge in the right direction, please don't hesitate to join our official [discord.js Server][discord].
+If you don't understand something in the documentation, you are experiencing problems, or you just need a gentle nudge in the right direction, please don't hesitate to join our official [discord.js Server][discord].
 
-[website]: https://discord.js.org/
+[website]: https://discord.js.org
 [website-source]: https://github.com/discordjs/discord.js/tree/main/apps/website
-[documentation]: https://discord.js.org/
+[documentation]: https://discord.js.org/docs/packages/core/stable
 [guide]: https://discordjs.guide/
 [guide-source]: https://github.com/discordjs/guide
 [guide-update]: https://discordjs.guide/additional-info/changes-in-v14.html