Added WinterCMS to content management systems (#2918)

README.md

@@ -674,6 +674,7 @@ _Related: [Blogging Platforms](#blogging-platforms), [Static Site Generators](#s
 - [TYPO3](https://typo3.org/) - Powerful and advanced CMS with a large community. ([Source Code](https://github.com/TYPO3/TYPO3.CMS)) `GPL-2.0` `PHP`
 - [Umbraco](https://umbraco.com/) - The friendly CMS. Free and open source with an amazing community. ([Source Code](https://github.com/umbraco/Umbraco-CMS)) `MIT` `.NET`
 - [Wagtail](https://wagtail.io/) - Django content management system focused on flexibility and user experience. ([Source Code](https://github.com/wagtail/wagtail)) `BSD-3-Clause` `Python`
+- [WinterCMS](https://wintercms.com/) - Speedy and secure content management system built on the Laravel PHP framework. ([Source Code](https://github.com/wintercms/winter)) `MIT` `PHP`
 - [WonderCMS](https://www.wondercms.com) - WonderCMS is the smallest flat file CMS since 2008. ([Demo](https://www.wondercms.com/demo), [Source Code](https://github.com/robiso/wondercms)) `MIT` `PHP`
 - [WordPress](https://wordpress.org/) - World's most-used blogging and CMS engine. ([Source Code](https://github.com/WordPress/WordPress)) `GPL-2.0` `PHP`
 - [WriteFreely](https://writefreely.org) - Writing software for starting a minimalist, federated blog — or an entire community. ([Source Code](https://github.com/writefreely/writefreely)) `AGPL-3.0` `Go`