Documentation/README requires update (see description)

[ArnobG2002]

Please cover the answers to the following questions in the documentation:

1. How does the camera rotation work?
   • alpha=0 looks the same as alpha=180 which looks the same as alpha=360
   • alpha=0 looking the same as alpha=360 makes sense, but in that sense, alpha=180 should give a black/blank screen since the camera is looking at the direction opposite to where the chessboard mesh is.

2. When sx=sy, the chessboard not appearing square. Why?
   • I have a feeling it is because of the area of the window that the trackbar conquers, leaving a rectangular area for showing the mesh when the whole window is a square. This is probably the same reason that the chessboard appears square in the README gifs when sx=sy (because in the GUI in the gifs, a square area is designated for the mesh).
3. What does 'focus' mean? What is its unit? I am not saying this is an issue but a reference or some explanation would be nice.