Add changelog heading + missing changelog line in 23.4

readme.txt

@@ -276,7 +276,9 @@ Your question has most likely been answered on our help center: [yoast.com/help/
 
 = 23.5 =
 
-Release date: 2024-09-17
+Release date: 2024-09-24
+
+Yoast SEO 23.5 brings more enhancements and bugfixes. [Find more information about our software releases and updates here](https://yoa.st/release-24-9-24).
 
 #### Enhancements
 
@@ -299,6 +301,7 @@ Yoast SEO 23.4 brings more enhancements and bugfixes. [Find more information abo
 * Adds _так_ to the words recognized by the _transition words_ assessment in Russian. Props to @pavelmai83.
 * Improves the schema output by following the specification for the _SearchAction_ more strictly.
 * Re-enables the script concatenation that was disabled to prevent a bug with WordPress 5.5.
+* Improves the look of the Yoast SEO metabox in the block editor by centering it and making it stand out more by using a background color.
 
 #### Bugfixes