Mark the package as targeting Tailwind CSS v3 (#79)

For Tailwind v4, use canonical_tailwind. This adds a README banner, updates
the mix.exs description, and adds a CHANGELOG entry so the v3 scope and the
v4 pointer surface on GitHub, hex.pm, and hexdocs.

Docs and metadata only, no code changes.

Author: aptinio

CHANGELOG.md

@@ -1,4 +1,11 @@
 
+# Changelog for v0.4.3
+
+TailwindFormatter targets Tailwind CSS v3. For Tailwind v4, use
+[canonical_tailwind](https://hex.pm/packages/canonical_tailwind), which sorts
+classes via the `tailwindcss` CLI and Phoenix LiveView's `attribute_formatters`
+API.
+
 # Changelog for v0.4.0
 
 TailwindFormatter v0.4.0 requires Elixir v1.15+.

README.md

@@ -4,6 +4,10 @@
 
 <!-- MDOC !-->
 
+> **This package targets Tailwind CSS v3.** For Tailwind v4, use
+> [`canonical_tailwind`](https://hex.pm/packages/canonical_tailwind), which sorts
+> classes via the `tailwindcss` CLI and Phoenix LiveView's `attribute_formatters` API.
+
 Opinionated sorting for [TailwindCSS](https://tailwindcss.com)
 classes used in HEEx templates and `~H` sigils.
 

mix.exs

@@ -10,7 +10,8 @@ defmodule TailwindFormatter.MixProject do
       version: @version,
       elixir: "~> 1.15",
       name: "TailwindFormatter",
-      description: "A Mix formatter that sorts your Tailwind classes",
+      description:
+        "Sorts Tailwind CSS v3 classes in HEEx templates. For Tailwind v4, use canonical_tailwind.",
       deps: deps(),
       docs: docs(),
       package: package(),