Update README.md

Author: mnapoli

README.md

@@ -4,6 +4,8 @@
 [![Latest Stable Version](https://poser.pugx.org/myclabs/php-enum/version.png)](https://packagist.org/packages/myclabs/php-enum)
 [![Total Downloads](https://poser.pugx.org/myclabs/php-enum/downloads.png)](https://packagist.org/packages/myclabs/php-enum)
 
+Maintenance for this project is [supported via Tidelift](https://tidelift.com/subscription/pkg/packagist-myclabs-php-enum?utm_source=packagist-myclabs-php-enum&utm_medium=referral&utm_campaign=readme).
+
 ## Why?
 
 First, and mainly, `SplEnum` is not integrated to PHP, you have to install the extension separately.