updated README.md

Author: susonwaiba

README.md

@@ -10,7 +10,7 @@ A development docker for every symfony project
 - Latest php7.4, php7.3, php7.2 and php7.1 supported
 - Latest database mariadb10, mongodb4 and other versions supported
 - Latest node14.x, node13.x, node12.x, ... supported
-- Included symfony, composer and node cli
+- Included symfony, composer, node cli and yarn cli
 - Included emailcatcher with smtp and web view
 - Support for PhpStorm or VSCode + WSL2/docker-desktop setup
 - Support for xdebug included check `.env` file