Rename addChessBoard() In SceneBoard file

Rename addChessBoard() to addChessBoardToDisplayForSize() in order to
be clear of what this function is actually doing. Also, add in some
comments to better id where in the file you are in because it will get
hard to know where are in the file as it gets bigger.  Furthermore,
came to the realization that all functions that have to with displaying
items on the screen should be in the SceneBoard file.
Rename setToInitialState In aSimpleChessGame Class

Rename setToInitialState() to setInitialGameState() in aSimpleChessGame
class in order to be clear of what it does in the class as well as add
in some more comments to tell what does setInitialGameState() do and
where in the file you are at.