Moderate Changes

In order:
* Tweaked __init__():
** For now, Tiles initially face down
** For now, Tiles initially have 0 for content
** Moved the self.string line up
** Gave the list of commented notes a title

* Modified note() function to not do anything if the card is face up

* Modified the flip function so that it works on a very basic and
rudimentary level. I'm still not sure how I'm going to build in
functionality for inbetween games just yet.

* Fixed the board so that it actually prints all the tiles (instead of
just the first few again and again)