   when tools must be shared between developers and not as deployment options.
   See `mix help archive.build` and `mix help escript.build` for more detail.
 
-  Shutting down a live system cleanly can be done by calling `System.stop/1`.
-  It will shut down all applications in the opposite order they are started.
-  Each application will then shutdown its top-level supervisor, if one is
-  available, which then shuts down its children.
-
-  From Erlang/OTP 19.1, a SIGTERM from the operating system will automatically
-  translate to `System.stop/0`. Erlang/OTP 20 gives user more explicit control
-  over OS signals via the `:os.set_signal/2` function.
-
-  Applications also provide an "application environment", which is how
-  applications are configured. The application environment can either be set
-  statically, via a configuration file, or dynamically via `put_env/3` and
-  friends.
-
-  Over the next sections, we will cover the "application environment" and
-  the "application module callback" in more detail.
-
   ## Application environment
 
   Once an application is started, OTP provides an application environment

  system. Instead, you start one or more applications, each with their own
  initialization and termination logic.

  Starting an application is done via the "application module callback", which
  is a module that defines the `start/2` function. The `start/2` function should
  then start a supervisor, which is often called as the top-level supervisor, since


      config :APP_NAME, hello: :brand_new_world

  Keep in mind configuration files are only useful to configure static
  values. For example, if you need to configure your applications based
  on the system environment, the file system or on database entries,
  then those configurations are better placed at runtime. For example,
  one may configure applications dynamically via `put_env/3`.

  Keep in mind that each application is responsible for its environment.
  Do not use the functions in this module for directly accessing or modifying
  the environment of other applications (as it may lead to inconsistent
  data in the application environment).
  """

  @doc """
