docs: added relevant further information

Author: mfranzke

README.md

@@ -26,4 +26,17 @@ This especially relates to (but doesn't exclude further Deutsche Bahn brand asse
 
 ## License
 
-This project is licensed under [Apache-2.0](LICENSE), Copyright 2023 by DB Systel GmbH.
+The DB source code is licensed under the Apache License, Version 2.0, January 2004;
+you may not use this file except in compliance with the License. You may obtain a copy
+of the Apache License at <https://apache.org/licenses/LICENSE-2.0>. The DB source code
+does not include any DB specific design assets like fonts, icons, trademarks, brandings, etc.
+
+[Apache 2.0 license](LICENSES/Apache-2.0.txt)
+
+All Deutsche Bahn AG (hereinafter “DB”) specific design assets like fonts, icons,
+trademarks, brandings, etc. (hereinafter “DB Designs”) are licensed under the following
+license agreement (the “DB Designs License”):
+
+[DB Designs License](LICENSES/LicenseRef-DB-Designs-License.txt)
+
+Furthermore we're using a font and icon font that have been release by third party in a [CC0 1.0 license](LICENSES/CC0-1.0.txt) and we're providing our test snapshots by this very same [CC0 1.0 license](LICENSES/CC0-1.0.txt).