fixed composer link (#11)

Author: petrparolek

README.md

@@ -20,7 +20,7 @@ Website 🚀 <a href="https://contributte.org">contributte.org</a> | Contact 
 
 ## Usage
 
-To install latest version of `contributte/validator` use [Composer](https://getcomposer.com).
+To install latest version of `contributte/validator` use [Composer](https://getcomposer.org).
 
 ```bash
 composer require contributte/validator