Added a lot of changes to Main.hs which make the game playable (though not yet winnable)

- Added game introduction text
- Added gameLoop which handles all of the input and calls the appropriate functions to handle that input
- Added handleMove function which handles invalid movement commands or creates a new player state based on valid movement commands and passes that new state to the eventHandler
- Added eventHandler function which produces appropriate output when the player is in the same room as the Wumpus or a trap or outputs the sense function and possible paths if not