* 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

* 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)

* keep both in gitignore, since the default still exist

* 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

* readme files for the repository and the app
* makefile ans the main entry and documentation
* remove create-react-app from client code

* change behaviour so that service still comes up regardless whether db connection
  can be established or not (see 12-Factor-App) - loosely tight to backing service
* instead, it will log to stderr hinting this issue
* successful port binding is still required

* introduce a test on the server to see if user creation works (backend process <-> db only;
  still needs a test that involves the router, too)
* main server process is no connection-aware and wont start if database is not reachable
* some renaming, cause it's more descriptive
* unify quote usage

* not needed since it is served by the backend (./../server)

* to gain more control over dependencies and how things are executed

* PUBLIC_URL should now be provided as env var

* update deps to latest and pin min node & npm version
* checkin lock files
* make server serve client to merge both into one in order to reduce complexity
* adjust CSP accordingly

* applied latest cra-template
* removed react-specific content

* Dockerfile
* k8s resources
* yarn.lock

src: https://github.com/aamirpinger/todo-app-client-server-kubernetes/commit/93be212a344ea910b0a13f1110975bfdfd306f3a