No start screen for the game

[AxlLind]

The game needs a basic start screen with contains the following:

• Start button. Sends user to the Main_Game scene

• Settings button, implement settings later.

• Highscores, implement later. Maybe using a Firebase database for this?

[AxlLind]

Added with the commit "Add start screen and temp settings/highscore". Forgot to reference issue.