chore: fix npm badge style in readme

README.md

@@ -8,7 +8,7 @@ MariaDB, PostgreSQL and SQLite databases.
 
 > Heavily inspired by [Doctrine](https://www.doctrine-project.org/) and [Nextras Orm](https://nextras.org/orm/).
 
-[![NPM version](https://img.shields.io/npm/v/mikro-orm.svg?style=plastic)](https://www.npmjs.com/package/mikro-orm)
+[![NPM version](https://img.shields.io/npm/v/mikro-orm.svg)](https://www.npmjs.com/package/mikro-orm)
 [![Chat on slack](https://img.shields.io/badge/chat-on%20slack-blue.svg)](https://join.slack.com/t/mikroorm/shared_invite/enQtNTM1ODYzMzM4MDk3LWM4ZDExMjU5ZDhmNjA2MmM3MWMwZmExNjhhNDdiYTMwNWM0MGY5ZTE3ZjkyZTMzOWExNDgyYmMzNDE1NDI5NjA)
 [![Downloads](https://img.shields.io/npm/dm/mikro-orm.svg)](https://www.npmjs.com/package/mikro-orm)
 [![Coverage Status](https://img.shields.io/coveralls/mikro-orm/mikro-orm.svg)](https://coveralls.io/r/mikro-orm/mikro-orm?branch=master)