Add missing changelog item

CHANGELOG.md

@@ -6,6 +6,16 @@ Changelog is rather internal in nature. See release notes for the public overvie
 
 <!-- [DO NOT REMOVE-USED BY GH ACTION] PASTE CHANGELOG -->
 
+- [#744]
+  - **Description:** Removes internal state management for checked & indeterminate in KCheckbox.
+  - **Products impact:** Updated API
+  - **Addresses:** https://github.com/learningequality/studio/issues/4636
+  - **Components:** KCheckbox
+  - **Breaking:** No
+  - **Impacts a11y:** No
+  - **Guidance:** If you use KCheckbox, it is your responsibility to handle the `change` event and update whether or not the given `checked` and `indeterminate` props reflect the reality that you expect.
+[#744]: https://github.com/learningequality/kolibri-design-system/pull/744
+
 - [#737]
   - **Description:** Bump KDS version to 4.4.1.
   - **Products impact:** -.