Done:
-icon added
-Save-Button implemented
--> App is now able to open, show and save changes
ISSUES;
 - UTF8-Encoding ToDO
 - OpenFileDialog with picture filter
 - solve the url-Images
 - validation of the picture's path -
UTF-Encoding (solution on XmlDocumentSettings enumeration)
Done: -
- OpenFileDialog with picture filter
--> App is now able to open, show and save changes
ISSUES;
  - UTF8-Encoding
 ToDO
  - solve the url-Images
 - UTF-Encoding (solution on XmlDocumentSettings enumeration)
 - Code documentation