Update README

Author: msaraiva

README.md

@@ -2,6 +2,14 @@
 
 Surface Wrappers for `Phoenix.HTML.Form` functions.
 
+> [!NOTE]
+> This library is maintained only for compatibility and does not accept new features.
+> We strongly recommend using the new built-in [<.form>](https://hexdocs.pm/phoenix_live_view/Phoenix.Component.html#form/)
+> component, along with [Phoenix.HTML.Form](https://hexdocs.pm/phoenix_html/Phoenix.HTML.Form.html) and
+> [Phoenix.HTML.FormField](https://hexdocs.pm/phoenix_html/Phoenix.HTML.FormField.html) structs. If you're
+> not able to update all your forms at once, then this library can be used as a safe fallback so you can
+> gradually replace them.
+
 ## Installation
 
 If [available in Hex](https://hex.pm/docs/publish), the package can be installed