* removed hack folder and with it all code to install deps
* reworked `make build` to show more explicitly what needs to be done when
  producing an artifact
* bumped node version dep to v14 (to make jest work again)
* adjusted readme
* suppress console output when running jest client tests

* 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

* adjust mongoose configuration
* documents more make targets in readme
* applied npm scripts convention of the client to the corresponding
  server scripts in order to be more consistent (`start` is now meant
  for local development)

* tech stack can be installed locally and will be used by app-related
  targets if available
* bumped minimal required npm version to 6.14 for server and client