WIP: Feature/#27 integration docs

Feature

Summary

This MR provides an enhanced README with information about:

• ways of how to integrate the viewer to GitLab pages or your own webserver
• an architecture diagram that explains how the viewer works
• completed the section on how to set up the Viewer from scratch
• expansion of the config section

Does the result of the MR comply to our "definition of done"?

• N/A

Use Cases

For everyone re-using the viewer for his/her project.

Documentation

• N/A

Changelog

• I added a statement to the CHANGELOG.

Related Tickets

Related

#27 (closed)

/cc Mathias Göbel, Frank Schneider, Michelle Weidling