Add monthly downloads

Author: Kirill Nesmeyanov

README.md

@@ -10,6 +10,7 @@
     <a href="https://packagist.org/packages/type-lang/parser"><img src="https://poser.pugx.org/type-lang/parser/require/php?style=for-the-badge" alt="PHP 8.1+"></a>
     <a href="https://packagist.org/packages/type-lang/parser"><img src="https://poser.pugx.org/type-lang/parser/version?style=for-the-badge" alt="Latest Stable Version"></a>
     <a href="https://packagist.org/packages/type-lang/parser"><img src="https://poser.pugx.org/type-lang/parser/v/unstable?style=for-the-badge" alt="Latest Unstable Version"></a>
+    <a href="https://packagist.org/packages/type-lang/parser"><img src="https://poser.pugx.org/type-lang/parser/d/monthly?style=for-the-badge" alt="Monthly Downloads"></a>
     <a href="https://raw.githubusercontent.com/php-type-language/parser/blob/master/LICENSE"><img src="https://poser.pugx.org/type-lang/parser/license?style=for-the-badge" alt="License MIT"></a>
 </p>
 <p align="center">