update README: note php 8.4 compatibility

As added in prettier#2422

Author: andyfowler

README.md

@@ -198,7 +198,7 @@ supported PHP version.
 You set the `phpVersion` to `composer` and this will only use the `composer.json` file to determine the php
 version, prettier will crash if the PHP cannot be determined.
 
-You can also set the `phpVersion` to a specific version, such as `7.4`, `8.0`, `8.1`, `8.2`, or `8.3`.
+You can also set the `phpVersion` to a specific version, such as `7.4`, `8.0`, `8.1`, `8.2`, `8.3` or `8.4`.
 
 **Please Note:** If the phpVersion is not set correctly for your environment, this plugin will produce code that could
 be incompatible with your PHP runtime. For example, if you are using PHP 7.4, but the plugin is set to PHP 8.3, it will