doc: remove plugins note from README

See thread at
#450 (comment),
the default plugins are still present.

[skip ci]

Author: flavorjones

Diff for: README.md

@@ -12,7 +12,6 @@
 - [Upgrading your application from Tailwind v3 to v4](#upgrading-your-application-from-tailwind-v3-to-v4)
   * [You don't _have_ to upgrade](#you-dont-_have_-to-upgrade)
   * [Upgrade steps](#upgrade-steps)
-  * [Plugins](#plugins)
   * [Troubleshooting](#troubleshooting)
 - [Developing with Tailwindcss](#developing-with-tailwindcss)
   * [Configuration and commands](#configuration-and-commands)
@@ -152,13 +151,6 @@ Done in 56ms
 If this doesn't succeed, it's likely that you've customized your Tailwind configuration and you'll need to do some work to make sure your application upgrades. Please read the [official upgrade guide](https://tailwindcss.com/docs/upgrade-guide)!
 
 
-### Plugins
-
-In Tailwind CLI v3, some Tailwind plugins were included by default in the CLI tool. However, in v4 these default plugins have been removed.
-
-In order to use any plugins with v4, either by declaring them in your (optional) config file or using the [`@plugin` directive](https://tailwindcss.com/docs/functions-and-directives#plugin-directive), it's necessary to install them using a local javascript package manager.
-
-
 ### Troubleshooting
 
 You may want to check out [TailwindCSS v4 - upgrade experience report · rails/tailwindcss-rails · Discussion #450](https://github.com/rails/tailwindcss-rails/discussions/450) if you're having trouble upgrading.