Fix typo in badge (#810)

Author: ShockwaveNN

README.md

@@ -1,5 +1,5 @@
 [![License](https://img.shields.io/badge/License-GNU%20AGPL%20V3-green.svg?style=flat)](https://www.gnu.org/licenses/agpl-3.0.en.html)
-![Platforms Windows | macOS | Linux](https://img.shields.io/badge/Platforms-Window%20%7C%20macOS%20%7C%20Linux-lightgrey.svg?style=flat) ![Release](https://img.shields.io/badge/Release-v6.4.2-blue.svg?style=flat)
+![Platforms Windows | macOS | Linux](https://img.shields.io/badge/Platforms-Windows%20%7C%20macOS%20%7C%20Linux-lightgrey.svg?style=flat) ![Release](https://img.shields.io/badge/Release-v6.4.2-blue.svg?style=flat)
 
 ## Overview