Added comments and minor change of order

[athanasiab]

• Added comments in files cube.js and cubeparts.css; in order for the code to be easier to read. Comments were made based on my personal understanding of the code and may differ from what the programmers of the project would add
• Changed the order of some items in "sideArray" (in cube.js) so that all faces' attributes follow the same order and also, changed the corresponding ones in cubeparts.css in order to have the same results as previously.

Both were done in order to make the code easier to read for programmers that want to help in the development of the project.