[Checkins] [zopefoundation/Zope] 180823: - make Zope Book chapter 11 work again

[Jens Vagelpohl]

  Branch: refs/heads/4.x
  Home:   https://github.com/zopefoundation/Zope
  Commit: 180823215d4b769c3d218b657418be1feaa98aac
      https://github.com/zopefoundation/Zope/commit/180823215d4b769c3d218b657418be1feaa98aac
  Author: Jens Vagelpohl <jens at netz.ooo>
  Date:   2020-06-17 (Wed, 17 Jun 2020)

  Changed paths:
    M docs/zopebook/Figures/zoo1.png
    M docs/zopebook/SimpleExamples.rst

  Log Message:
  -----------
  - make Zope Book chapter 11 work again