Merge branch '6160-update-readme-md' into 'develop'

Resolve "Update readme.md"

Closes #6160

See merge request ispconfig/ispconfig3!1481

CONTRIBUTING.md

@@ -9,6 +9,7 @@ This document is under development and will be continuously improved.
 * If you want to report several bugs or request several features, open a separate issue for each one of them.
 
 # Branches
+* If you are a new user, please send an email to: dev [at] ispconfig [dot] org to receive rights to fork the project.
 * Please create an issue for each contribution you want to make.
 * Do not put multiple contributions into a single branch and merge request. Each contribution should have it's own branch.
 * Do not use the develop branch in your forked project for your contribution. Create a separate branch for each issue.

README.md

 # ISPConfig - Hosting Control Panel
-![alt text](https://www.ispconfig.org/wp-content/themes/ispconfig/images/ispconfig_logo.png "") \
+![ISPConfig logo](https://www.ispconfig.org/wp-content/themes/ispconfig/images/ispconfig_logo.png "") \
 Development branch: [![pipeline status](https://git.ispconfig.org/ispconfig/ispconfig3/badges/develop/pipeline.svg)](https://git.ispconfig.org/ispconfig/ispconfig3/commits/develop)
 
 ## Functions
 - Manage multiple servers from one control panel
 - Single server, multiserver and mirrored clusters.
-- Webserver management (Apache2 and nginx)
+- Webserver management
 - Mailserver management
-- DNS server management (BIND and PowerDNS)
+- DNS server management
 - Virtualization (OpenVZ)
 - Administrator, reseller, client and mailuser login
-- Open Source software (BSD license)
+- Open Source software ([BSD license](LICENSE))
 
 ## Supported daemons
-- HTTP: Apache2 and nginx
+- HTTP: Apache2 and NGINX
 - HTTP stats: Webalizer, GoAccess and AWStats
 - Let's Encrypt: Acme.sh and certbot
 - SMTP: Postfix
 - POP3/IMAP: Dovecot
 - Spamfilter: Rspamd and Amavis
 - FTP: PureFTPD
-- DNS: BIND9 and PowerDNS
+- DNS: BIND9 and PowerDNS[^1]
 - Database: MariaDB and MySQL
 
+[^1]: not actively tested
+
 ## Supported operating systems
 - Debian 9, 10, and testing
 - Ubuntu 16.04 - 20.04
 - CentOS 7 and 8
 
 ## Auto-install script
-You can install ISPConfig with our official autoinstaller: https://git.ispconfig.org/ispconfig/ispconfig-autoinstaller/-/blob/master/README.md
+You can install the "Perfect Server" with ISPConfig using [our official autoinstaller](https://www.howtoforge.com/ispconfig-autoinstall-debian-ubuntu/)
 
 ## Migration tool
-The Migration Tool helps you to import data from other control panels (currently ISPConfig 2 and 3 – 3.2, Plesk 10 – 12.5, Plesk Onyx, CPanel** and Confixx 3). For more information, see https://www.ispconfig.org/add-ons/ispconfig-migration-tool/
+The Migration Tool helps you to import data from other control panels (currently ISPConfig 2 and 3 – 3.2, Plesk 10 – 12.5, Plesk Onyx, CPanel[^2] and Confixx 3). For more information, see https://www.ispconfig.org/add-ons/ispconfig-migration-tool/
 
-** The Migration Toolkit contains now beta support for migrating CPanel to ISPConfig.
+[^2]: The Migration Toolkit now contains beta support for migrating CPanel to ISPConfig.
 
 ## Documentation
 You can support ISPConfig development by buying the manual: https://www.ispconfig.org/documentation/
 
 ## Contributing
-If you like to contribute to the ISPConfig development, please send an email to: dev [at] ispconfig [dot] org.
+If you like to contribute to the ISPConfig development, please read the contributing guidelines: [CONTRIBUTING.MD](CONTRIBUTING.md)
+