Add sleepTime kwarg to drawGrid

It'll pause before drawing by the input time. Mostly for my own personal
debugging.
Adding a simple maze game

Manually move through the maze using 'up', 'down', 'left', 'right'.
until you reach the end.
Adding maze-solving methods

So far only brute-force methods (which take between 1800 - 4200 steps
for a 10x10 maze) and right-hand rule method (which takes between 150 -
190 iterations for a 10x10 maze)