[Documentation] Add some architectural views in the project

[Madunguin]

**Is your feature request related to a problem? Please describe.
My team and I believe that adding some architectural views will help new developers collaborate on the project or use the program more easily.

Describe the solution you'd like
We think that adding then in the Read Me will help then.

Additional context
We are a group of students and in our project we had to investigate what is eXist-db, and we think really think that with these diagrams more people will understand how eXist works .

[adamretter]

Sounds good. It might be better to place them in a separate Markdown file and like them from README.md in the same way that https://github.com/eXist-db/exist/blob/develop/CONTRIBUTING.md is

[Madunguin]

Thanks, We are working on the Markdown.

[Madunguin]

We have already created the Markdown file. What do you want us to do with it?
Do you want me to send it to you in some way so you can review it and see if it is suitable to be added as extra documentation for the project?

[joewiz]

@Madunguin Great! You are welcome to submit a PR - or post the content into this issue as your next reply, for discussion about the best destination for the content.