Small Update (Commented Code)

Hi!

I've made a small update to the code, but a very necessary one! Now the scripts for each algorithm are completely commented, with an explanation of what is happening in each step.

Maybe I overdid it, but I wasn't sure how clear the code was, and it can be a bit tricky to understand the algorithms mechanisms. If you read all of it and is still confused about the how the algorithms work, I highly recommend to check Jamis Buck's blog about Maze Algorithms. There is an in-depth explanation (with pictures!) of all algorithms I used, and a lot more.

Thanks!