Update release notes for Dash user contributions

- fixes #9370

CONTRIBUTORS.rst

@@ -644,6 +644,7 @@ Contributors
 * Victoria Poromon
 * Dokua Asiedu
 * Darrel O'Pry
+* Mary Ayobami
 
 Translators
 ===========

docs/releases/4.2.md

@@ -15,7 +15,7 @@ depth: 1
 ### Other features
 
  * Add custom permissions section to permissions documentation page (Dan Hayden)
- * Wagtail's documentation (v2.9 to v2.13) has been updated on [Dash user contributions](https://github.com/Kapeli/Dash-User-Contributions) for [Dash](https://kapeli.com/dash) or [Zeal](https://zealdocs.org/) offline docs applications (Damilola Oladele)
+ * Wagtail's documentation (v2.9 to v4.0) has been updated on [Dash user contributions](https://github.com/Kapeli/Dash-User-Contributions) for [Dash](https://kapeli.com/dash) or [Zeal](https://zealdocs.org/) offline docs applications (Damilola Oladele, (Mary Ayobami)
  * Switch to using [Willow](https://github.com/wagtail/Willow/) instead of Pillow for images (Darrel O'Pry)
 
 ### Bug fixes