Update the readme to link to tool websites

README.md

@@ -15,9 +15,9 @@ You can also configure the plugin to fix the issues using either
 
 Requirements for this plugin, should you want all the options to work:
 
-- PHP_CodeSniffer 3.5+ (potentially works with lower versions, but this hasn’t been tested) - Install
-- PHPMD 2.8+ (potentially works with lower versions, but this hasn’t been tested) - Install
-- PHP CS Fixer version 2.6+ (potentially works with lower versions, but this hasn’t been tested) - Install
+- [PHP_CodeSniffer](https://github.com/squizlabs/PHP_CodeSniffer)  3.5+
+- [PHPMD](https://phpmd.org) 2.8+
+- [PHP CS Fixer](https://github.com/PHP-CS-Fixer/PHP-CS-Fixer) 2.6+
 
 This plugin has been tested on:
 
@@ -28,6 +28,8 @@ This plugin has been tested on:
 - Sublime Text 3
 - Sublime Text 4
 
+It may work with other versions, but we cannot confirm that.
+
 ## Installation
 
 Use Sublime Text’s Package Control (Tools -> Command Palette -> Package Control: Install Package -> Phpcs) to install this plugin. This is the recommended installation path.