add Snake.Console.fs
remove Snake.Console.fs
add Snake.Console.fsproj
rename (Snake to Snake.Engine).fsproj
introduce (command : Direction option)
Revert "introduce (command : Direction option)"

This reverts commit c3723a435f01591efc02e73fcb0491a606e8b4e8.
rename print_char_to_cell to print_char
separate Console and Engine
remove ``...``-s
set Snake.Engine Assembly Name
introduce: exists element list