Run the notebook code within the Livebook node itself.
This is reserved for specific cases where there is no option
of starting a separate Elixir runtime (for example, on embedded
devices or cases where the amount of memory available is
limited). Prefer the "Standalone" runtime whenever possible.
Warning:
any module that you define will be defined globally until
you restart Livebook. Furthermore, code in one notebook
may interfere with code from another notebook.