Update nginx version in badge

Author: TrafeX

README.md

@@ -15,7 +15,7 @@ Repository: https://github.com/TrafeX/docker-php-nginx
 * Follows the KISS principle (Keep It Simple, Stupid) to make it easy to understand and adjust the image to your needs
 
 [![Docker Pulls](https://img.shields.io/docker/pulls/trafex/php-nginx.svg)](https://hub.docker.com/r/trafex/php-nginx/)
-![nginx 1.18.0](https://img.shields.io/badge/nginx-1.20-brightgreen.svg)
+![nginx 1.20](https://img.shields.io/badge/nginx-1.20-brightgreen.svg)
 ![php 8.0](https://img.shields.io/badge/php-8.0-brightgreen.svg)
 ![License MIT](https://img.shields.io/badge/license-MIT-blue.svg)