Add changelog #9558

CHANGELOG.txt

@@ -45,6 +45,7 @@ Changelog
  * Docs: Improve 'first wagtail site' tutorial (Akua Dokua Asiedu)
  * Docs: Grammatical adjustments of `page models` usage guide (Damilola Oladele)
  * Docs: Add class inheritance information to StreamField block sreference (Temidayo Azeez)
+ * Docs: Document the hook `register_image_operations` and add an example of a custom Image filter (Coen van der Kamp)
  * Maintenance: Remove unsquashed `testapp` migrations (Matt Westcott)
  * Maintenance: Upgrade to Node 18 for frontend build tooling (LB (Ben) Johnston)
  * Maintenance: Run Python tests with coverage and upload coverage data to codecov (Sage Abdullah)

docs/releases/4.2.md

@@ -61,6 +61,7 @@ depth: 1
  * Improve 'first wagtail site' tutorial (Akua Dokua Asiedu)
  * Grammatical adjustments of `page models` usage guide (Damilola Oladele)
  * Add class inheritance information to StreamField block sreference (Temidayo Azeez)
+ * Document the hook [`register_image_operations`](register_image_operations) and add an example of a [custom Image filter](custom_image_filters) (Coen van der Kamp)
 
 ### Maintenance