Release v1.20.0

Changelog

ebe4e9b 🏁 Releasing version 1.20.0
1391832 Merge pull request #273 from dlsc-software-consulting-gmbh/staging
491b02a Merge pull request #272 from dlsc-software-consulting-gmbh/feature-add-doc-model-2
e89a2fd Add new model Documentation
c281b06 Fix broken link as reported in #270
c1193da Merge pull request #269 from dlsc-software-consulting-gmbh/staging
294c603 Merge pull request #268 from rladstaetter/staging
10e83f0 Downloads: updates download links and readme for LogoRRR