Move Stimulus adoption changelog entries to their own section

docs/releases/5.1.md

@@ -30,6 +30,15 @@ Thank you to Damilola for his work, and to Google for sponsoring this project.
 
 The `wagtail start` command now supports an optional `--template` argument that allows you to specify a custom project template to use. This is useful if you want to use a custom template that includes additional features or customisations. For more details, see [the project template reference](/reference/project_template). This feature was developed by Thibaud Colas.
 
+### Extend Stimulus adoption
+
+As part of tackling Wagtail’s technical debt and improving [CSP compatibility]([Title](https://github.com/wagtail/wagtail/issues/1288)), we have continued extending our usage of Stimulus, based on the plans laid out in [RFC 78: Adopt Stimulus](https://github.com/wagtail/rfcs/pull/78).
+
+* Migrate Tagit initialisation to a Stimulus Controller (LB (Ben) Johnston)
+* Migrate legacy dropdown implementation to a Stimulus controller (Thibaud Colas)
+* Migrate header search behaviour to `w-swap`, a Stimulus controller (LB (Ben) Johnston)
+* Replace Bootstrap tooltips with a new `w-tooltip` Stimulus controller (LB (Ben) Johnston)
+
 ### Other features
 
  * Mark calls to `md5` as not being used for secure purposes, to avoid flagging on FIPS-mode systems (Sean Kelly)
@@ -111,13 +120,10 @@ The `wagtail start` command now supports an optional `--template` argument that
  * Convert page listing to a class-based view (Matt Westcott)
  * Clean up page reports and type usage views to be independent of page listing views (Matt Westcott)
  * Refactor "More" dropdowns, locale selector, "Switch locales", page actions, to use the same dropdown component (Thibaud Colas)
- * Migrate Tagit initialisation to a Stimulus Controller (LB (Ben) Johnston)
  * Refactor GroupPagePermission to use Django's Permission model (Sage Abdullah)
  * Convert the `CONTRIBUTORS` file to Markdown (Dan Braghis)
  * Move `django-filter` version upper bound to v24 (Yuekui)
  * Update Pillow dependency to allow 10.x, only include support for >= 9.1.0 (Yuekui)
- * Migrate header search behaviour to `w-swap`, a Stimulus controller (LB (Ben) Johnston)
- * Replace Bootstrap tooltips with a new `w-tooltip` Stimulus controller (LB (Ben) Johnston)
  * Replace ModelAdmin history header human readable date template tag (LB (Ben) Johnston)
 
 ## Upgrade considerations