[Checkins] [zopefoundation/zope.schema] ee3aa4: Add documentation for #86.

[Michael Howitz]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/zope.schema
  Commit: ee3aa418d1c9425dccf3fbb210924b77340f04a0
      https://github.com/zopefoundation/zope.schema/commit/ee3aa418d1c9425dccf3fbb210924b77340f04a0
  Author: Michael Howitz <mh at gocept.com>
  Date:   2020-02-28 (Fri, 28 Feb 2020)

  Changed paths:
    M docs/fields.rst

  Log Message:
  -----------
  Add documentation for #86.