Fix issue 'Statusbar automatically sets to 2 #24'

#24

add item_limit (#20)

add 'Q' : quit and close game

Change new ball creation conditions : A solution to the problem that …

…no new ball is created when there is a vertical movement item.

[bugfix] Grouping autocmds to hide cursors.

Modify the rule to move the vertically moving ball infinitely. (#17)

[bugfix] disable fold in game. (#14)

fix width 80

fix width 80

updated README