delete drawing using backspace

Dependencies

• [2] 6PUNJS5B backspace
• [*] OTIBCAUJ love2d scaffold

Change contents

• edit in main.lua at line 474
  [2.139]

  [2.139]
  + elseif type(lines[#lines]) == 'table' then

  + table.remove(lines) -- we'll add undo soon