documentation issue: plone.autoform.directives -> plone.supermodel.directives

[spereverde]

When trying to create a dexterity behavior I was following this guideline:
https://github.com/plone/plone.app.dexterity/blame/master/docs/behaviors/creating-and-registering-behaviors.rst
But the directives import gave an error (using Plone 5.1.2)
traceback:

   ZopeXMLConfigurationError: File "/opt/etc/buildout/u0045445/eggs/Products.CMFPlone-5.1.2.1-py2.7.egg/Products/CMFPlone/configure.zcml", line 105.2-109.8
    ZopeXMLConfigurationError: File "/.autofs/homes/users/u0045445/workspace/plone5-buildout/src/kuleuven.footer/src/kuleuven/footer/configure.zcml", line 20.2-20.35
    ZopeXMLConfigurationError: File "/.autofs/homes/users/u0045445/workspace/plone5-buildout/src/kuleuven.footer/src/kuleuven/footer/behaviors.zcml", line 8.4-13.10
    AttributeError: 'module' object has no attribute 'fieldset'

the line
from plone.autoform import directives
https://github.com/plone/plone.app.dexterity/blame/master/docs/behaviors/creating-and-registering-behaviors.rst#L67
should be changed to
from plone.supermodel import directives

This would then make the example code differ from the collective.gtags package you are referring too, which might make this very confusing, so I'm hesitant to just change this in the documentation before discussing this...