Update README.md

Rewrite requirements section to leave out versions and only have to change it in one place on the wiki going forward.

README.md

@@ -201,8 +201,9 @@ See the [ChangeLog](https://github.com/Dolibarr/dolibarr/blob/develop/ChangeLog)
 
 
 ### System Environment / Requirements
-
-- Works with PHP 5.6+ and MariaDB 5.0.3+, MySQL 5.0.3+ or PostgreSQL 8.1.4+ (See requirements on the [Wiki](https://wiki.dolibarr.org/index.php/Prerequisite))
+(See exact requirements on the [Wiki](https://wiki.dolibarr.org/index.php/Prerequisite))
+- PHP
+- MariaDB, MySQL or PostgreSQL 
 - Compatible with all Cloud solutions that match PHP & MySQL or PostgreSQL prerequisites.