draw lines by default

Dependencies

• [2] JCSLDGAH beginnings of support for multiple shapes
• [3] 2C7CTIQY make space for multiple kinds of width
• [4] JVRL5TWL store device-independent coordinates inside drawings
• [*] OTIBCAUJ love2d scaffold

Change contents

• replacement in main.lua at line 37
  [2.1241]→[2.1241:1267](∅→∅)
  − current_mode = 'freehand'
  [2.1241]

  [3.3]
  + current_mode = 'line'