Modified Application, Game, and GameSupervisor. Replaced Supervisor with DynamicSupervisor.

Finished Game module and configured application.ex to start Registry for tracking unique keys

Adding new player to Game module (GenServer) works

Added Game module and finished GenServer basics

Finished module Rules (Chapter 3)

Finished Board and Island modules

Modified Coordinate and Guesses modules

Created simple Board module

Added Coordinate, Guesses, and Island modules

Initial commit for new Mix project