ensure integer coordinates

Dependencies

• [2] DLQMM265 scroll past first page
• [3] 7IKRRESB longer names for indices in long loops
• [4] XX7G2FFJ intermingle freehand line drawings with text
• [*] OTIBCAUJ love2d scaffold

Change contents

• replacement in main.lua at line 112
  [2.588]→[2.588:608](∅→∅)
  − y = y+15*Zoom
  [2.588]

  [2.608]
  + y = math.floor(y+15*Zoom)