ADD: comments added

README.md

 ## Mermaid
 
+[Mermaid](https://mermaid.js.org/) can be used to create diagrams like with [Graphviz](https://graphviz.org/) directly embedded into markdown-files.
+
 ```mermaid
   graph TD;
       A-->B;
@@ -8,8 +10,10 @@
       C-->D;
 ```
 
-
 ## PlantUML
+
+[PlantUML](https://plantuml.com/en/) can be used to create UML-diagrams directly embedded into markdown-files.
+
 ```plantuml
 Alice -> Bob: Authentication Request
 Bob --> Alice: Authentication Response
@@ -26,6 +30,6 @@ Car -- Person : < owns
 
 ## Rendered on Webservice
 
-![Class Diagram](http://www.plantuml.com/plantuml/proxy?src=https://raw.githubusercontent.com/Zingam/Markdown-Document-UML-Use-Test/master/UML/Instance.puml)
+For **public** projects it's possible to let a [webserver](http://www.plantuml.com/plantuml/proxy?src=) render the UML's. This allows to use external files for the defintion of these UML-diagrams.
 
-![Class Diagram](http://www.plantuml.com/plantuml/proxy?src=https://code.fbi.h-da.de/stfeschei/uml-in-markdown/-/raw/main/Instance.puml)
+![Class Diagram](http://www.plantuml.com/plantuml/proxy?src=https://code.fbi.h-da.de/stfeschei/uml-in-markdown/-/raw/main/UML/UML.puml)