Add reference to architecture diagrams for high-level packages

[alexkarezin]

Is your suggestion for improvement related to a problem? Please describe.
Not a problem, requesting an addition to Wiki page

Describe the solution you'd like
Add reference to architecture diagrams for model, gui and logic packages
https://sourcespy.com/github/jabref/

Additional context
Not sure how to submit PR for Wiki page. Please advise. I have staged the change here.
alexkarezin/jabref-wiki@713d119

[tobiasdiez]

Thanks, these diagrams look really cool. I added the link: https://github.com/JabRef/jabref/wiki/High-Level-Documentation