remove tine20

- all links now redirect to https://www.tine-groupware.de/, n english homepage available
- no setup instructions/documentation available, unsure what to do wih the source code

README.md

@@ -1036,7 +1036,6 @@ _Related: [Groupware](#groupware)_
 - [Openmeetings](https://openmeetings.apache.org/index.html) - Openmeetings provides video conferencing, instant messaging, white board, collaborative document editing and other groupware tools using API functions of the Red5 Streaming Server for Remoting and Streaming. ([Source Code](https://openmeetings.apache.org/scm.html)) `Apache-2.0` `Java`
 - [SOGo](https://sogo.nu/) - SOGo offers multiple ways to access the calendaring and messaging data. CalDAV, CardDAV, GroupDAV, as well as ActiveSync, including native Outlook compatibility and Web interface. ([Demo](https://demo.sogo.nu/SOGo/), [Source Code](https://github.com/inverse-inc/sogo)) `LGPL-2.1` `Objective-C`
 - [SuiteCRM](https://suitecrm.com) - The award-winning, enterprise-class open source CRM. ([Source Code](https://github.com/salesagility/SuiteCRM)) `AGPL-3.0` `PHP`
-- [Tine 2.0](https://www.tine20.org) - Contacts, Calendar, Tasks, WebDAV, ActiveSync, VOIP, Mail-Client, CRM, Sales, Projects, Timetracker. ([Demo](https://demo.tine20.net), [Source Code](https://packages.tine20.com/maintenance/source/)) `AGPL-3.0/Other` `PHP`
 - [Tracim](https://github.com/tracim/tracim) - Collaborative Platform for team collaboration: file,threads,notes,agenda,etc. `AGPL-3.0/LGPL-3.0/MIT` `Python`
 - [Zimbra Collaboration](https://www.zimbra.com/) - Email, calendar, collaboration server with Web interface and lots of integrations. ([Source Code](https://github.com/zimbra)) `GPL-2.0/CPAL-1.0` `Java`