doc: update README.md

Author: didoda

README.md

@@ -12,7 +12,7 @@ BEdita PHP Official PHP SDK
 
 ## Prerequisites
 
-* PHP 7.4, 8.0, 8.1, 8.2, 8.3
+* PHP >= 8.1
 * [Composer](https://getcomposer.org/doc/00-intro.md#installation-linux-unix-osx)
 
 ## Install