document some editor constants

Dependencies

• [2] MXXCTVXW document facilities for buttons on screen
• [*] N2NUGNN4 include a brief reference enabling many useful apps
• [*] H5UZI3YN editor documentation

Change contents

• edit in reference.md at line 233
  [5.2345]

  [2.18]
  +

  + Some constants that affect editor behavior:

  + * `Margin_top`, `Margin_left`, `Margin_right` are integers in pixel units that

  + affect where the editor is drawn on window (it always extends to bottom of

  + window as needed)

  + * `Drawing_padding_top` and `Drawing_padding_bottom` affect spacing around

  + drawings.
• edit in reference.md at line 241
  [2.19]

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  + * Various color constants are represented as tables with r/g/b keys:

  + * `Text_color`, `Cursor_color`, `Highlight_color` for drawing text.

  + * `Stroke_color`, `Current_stroke_color` for line drawings.

  + * `Icon_color` affects the color of the little mode icon on the top right of

  + a drawing.

  + * `Current_name_background_color` manages the color when naming points using

  + `ctrl+n`.

  + * `Focus_stroke_color` affects the color of a point or line when you hover

  + over it.

  + * `Help_color` and `Help_background_color` affect the color of online help

  + within line drawings.

  +