planning out cursor up/down over wrapped lines

Dependencies

• [2] 242L3OQX bugfix: ensure Cursor_line is always on a text line
• [3] A2TQYJ6J .
• [*] BULPIBEG beginnings of a module for the text editor
• [*] XNFTJHC4 split keyboard handling between Text and Drawing
• [*] FS2ITYYH record a known issue

Change contents

• edit in text.lua at line 216
  [6.4030]

  [6.4030]
  + -- previous text line
• edit in text.lua at line 232
  [6.4509]

  [6.4509]
  + -- next text line
• replacement in README.md at line 10
  [2.1417]→[2.1417:1583](∅→∅)
  − * If there's no line of text at the bottom of the file, one will be

  − created.

  − So far this app isn't really designed for all-drawing files. I'm really just
  [2.1417]

  [2.1583]
  + * If there's no line of text at the top of the file, you may not be able

  + to scroll back up to the top with page-up.

  + So far this app isn't really designed for drawing-heavy files. For now I'm