Reshuffle 5.2 upgrade consideration notes

* It's unclear why the imghdr change affects developers, or what action if any they should take - I don't think this needs a note at all
* Changes to menu hooks really come under the category of "Wagtail customisations", not "Changes affecting all projects"

docs/releases/5.2.md

@@ -202,52 +202,6 @@ As part of our [adoption of Stimulus](https://github.com/wagtail/rfcs/blob/main/
  * Add better deprecation warnings to the `search.Query` & `search.QueryDailyHits` model, move final set of templates from the admin search module to the search promotions contrib module (LB (Ben) Johnston)
 
 
-## Upgrade considerations - changes affecting all projects
-
-### Removal of `imghdr` and upgrade to `Willow`
-
-[`imghdr`](https://docs.python.org/3/library/imghdr.html) is deprecated, and will be removed in Python 3.13.
-
-Wagtail now uses the Willow feature of providing the image MIME type, which uses the [`filetype`](https://pypi.org/project/filetype/) package.
-
-### Adoption of `classname` convention for `MenuItem` related classes and hooks
-
-Wagtail `MenuItem` and menu hooks have been updated to use the more consistent naming of `classname` (singular) instead of `classnames` (plural), a convention that started in Wagtail 4.2.
-
-The current `classnames` keyword argument naming will be supported, but will trigger a deprecation warning. Support for this variant will be removed in a future release.
-
-The following classes will adopt this new convention.
-
--   `admin.menu.MenuItem`
--   `admin.ui.sidebar.ActionMenuItem`
--   `admin.ui.sidebar.LinkMenuItem`
--   `admin.ui.sidebar.PageExplorerMenuItem`
--   `contrib.settings.registry.SettingMenuItem`
-
-The following hooks usage may be impacted if `classnames` were used when generating menu items.
-
--   `register_admin_menu_item`
--   `register_settings_menu_item`
-
-### Example
-
-```python
-from django.urls import reverse
-
-from wagtail import hooks
-from wagtail.admin.menu import MenuItem
-
-@hooks.register('register_admin_menu_item')
-def register_frank_menu_item():
-  return MenuItem(
-    'Frank',
-    reverse('frank'),
-    icon_name='folder-inverse',
-    order=10000,
-    classname="highlight-menu" # not classnames=...
-  )
-```
-
 ## Upgrade considerations - deprecation of old functionality
 
 ### Legacy moderation system is deprecated
@@ -277,6 +231,44 @@ If you use any of the above features, remove them or replace them with the equiv
 
 ## Upgrade considerations - changes affecting Wagtail customisations
 
+### Adoption of `classname` convention for `MenuItem` related classes and hooks
+
+Wagtail `MenuItem` and menu hooks have been updated to use the more consistent naming of `classname` (singular) instead of `classnames` (plural), a convention that started in Wagtail 4.2.
+
+The current `classnames` keyword argument naming will be supported, but will trigger a deprecation warning. Support for this variant will be removed in a future release.
+
+The following classes will adopt this new convention.
+
+-   `admin.menu.MenuItem`
+-   `admin.ui.sidebar.ActionMenuItem`
+-   `admin.ui.sidebar.LinkMenuItem`
+-   `admin.ui.sidebar.PageExplorerMenuItem`
+-   `contrib.settings.registry.SettingMenuItem`
+
+The following hooks usage may be impacted if `classnames` were used when generating menu items.
+
+-   `register_admin_menu_item`
+-   `register_settings_menu_item`
+
+#### Example
+
+```python
+from django.urls import reverse
+
+from wagtail import hooks
+from wagtail.admin.menu import MenuItem
+
+@hooks.register('register_admin_menu_item')
+def register_frank_menu_item():
+  return MenuItem(
+    'Frank',
+    reverse('frank'),
+    icon_name='folder-inverse',
+    order=10000,
+    classname="highlight-menu" # not classnames=...
+  )
+```
+
 ### Edit and delete URLs in `ModelViewSet` changed to allow non-integer primary keys
 
 To accommodate models with non-integer primary keys, the URL patterns for the edit and delete views in {class}`~wagtail.admin.viewsets.model.ModelViewSet` have been changed.