[Snek] [keith-packard/snek] c03463: Remove offensive wording

[Keith Packard]

  Branch: refs/heads/main
  Home:   https://github.com/keith-packard/snek
  Commit: c0346360a63677ecba966b145a515eb63fa283f2
      https://github.com/keith-packard/snek/commit/c0346360a63677ecba966b145a515eb63fa283f2
  Author: Keith Packard <keithp at keithp.com>
  Date:   2020-06-04 (Thu, 04 Jun 2020)

  Changed paths:
    M chips/samd21/samd21.h
    M doc/lessons/lesson-4/lesson-4-washing-machine.adoc
    M snek-print.c

  Log Message:
  -----------
  Remove offensive wording

Signed-off-by: Keith Packard <keithp at keithp.com>