Print and screen versies

This commit presents both print and screen versions of the main `idris` tutorial. Both versions use the same content, but have a different setup w.r.t paper size, and font size.

+ Print :: A4 with fullpage, and normal size fonts.
+ Screen :: (6in x 9in) and reduce margins, and small fonts for code and stdout.

The screen page size was sourced from guidance from the Memoir package of LaTeX, and is the same page size (IIRC) us for the screen version of the HoTT book.