- keeping both: mermaid + images

- since github is not supporting mermaid for their markdown rendering

* glow is kinda distracting
* original test for title content prevents utilizing a change of
this characteristic form being used for demonstration purposed. The
additional test makes testing for the title more flexible and not
relying on its content

* adjust app readme
* revert change in server 'scripts'
* renamed 'stack' into 'hack' and split up Makefile into two to better separate
  devops scenarios from scoped deps management
* updated readme according to the make target changes

* fix file name typo
* remove logs in test do reduce noise
* prevent 'connection established' log in test mode to reduce noise
* rename test to make it more obvious that it does not require (or create)
  a user object

Added DB-Test

* update mongoose, jest and nodemon to address security alerts triggered
  by dependabot
* 'test' target had a bug introduced by using wrong syntax
* renamed server scripts to clarify the distinction between invocations
  in local development, CI and actual operations

ESLint is only part of the application frontend and only invoked implicitly during build time