Docs - Add AbstractUser import to custom user model

- `from django.contrib.auth.models import AbstractUser`
- revise a previous changelog entry to clarify 'clean up' vs 'fix'

CHANGELOG.txt

@@ -25,7 +25,8 @@ Changelog
  * Allow `register_page_action_menu_item` and `construct_page_action_menu` hooks to override the default menu action (Rahmi Pruitt, Matt Westcott)
  * Add docs table template rendering example (Matt Westcott)
  * Add blog about image uploads in Wagtail forms to third party tutorial documentation (a-mere-peasant)
- * Fix multiple minor documentation issues (David T Thompson, ryanomor, kailwallin)
+ * Clean up multiple minor documentation issues (David T Thompson, ryanomor, kailwallin)
+ * Add AbstractUser import to custom user model documentation (LB (Ben Johnston))
  * Fix: Added line breaks to long filenames on multiple image / document uploader (Kevin Howbrook)
  * Fix: Added https support for Scribd oEmbed provider (Rodrigo)
  * Fix: Changed StreamField group labels color so labels are visible (Catherine Farman)

docs/advanced_topics/customisation/custom_user_models.rst

@@ -12,6 +12,8 @@ two fields. The foreign key references another model (not shown).
 
 .. code-block:: python
 
+  from django.contrib.auth.models import AbstractUser
+  
   class User(AbstractUser):
       country = models.CharField(verbose_name='country', max_length=255)
       status = models.ForeignKey(MembershipStatus, on_delete=models.SET_NULL, null=True, default=1)

docs/releases/2.7.rst

@@ -44,7 +44,8 @@ Other features
  * Allow ``register_page_action_menu_item`` and ``construct_page_action_menu`` hooks to override the default menu action (Rahmi Pruitt, Matt Westcott) - thanks to `The Motley Fool <https://www.fool.com/>`_ for sponsoring review of this feature
  * Add docs table template rendering example (Matt Westcott)
  * Add blog about image uploads in Wagtail forms to third party tutorial documentation (a-mere-peasant)
- * Fix multiple minor documentation issues (David T Thompson, ryanomor, kailwallin)
+ * Clean up multiple minor documentation issues (David T Thompson, ryanomor, kailwallin)
+ * Add AbstractUser import to custom user model documentation (LB (Ben Johnston))
 
 
 Bug fixes