Clean up whitespace items in documentation markdown

docs/advanced_topics/accessibility_considerations.md

@@ -148,7 +148,6 @@ To customize how the checker is run (such as what rules to test), you can define
 
 For example, Axe's [`p-as-heading`](https://github.com/dequelabs/axe-core/blob/develop/lib/checks/navigation/p-as-heading.json) rule evaluates combinations of font weight, size, and italics to decide if a paragraph is acting as a heading visually. Depending on your heading styles, you might want Axe to rely only on font weight to flag short, bold paragraphs as potential headings.
 
-
 ```python
 from wagtail.admin.userbar import AccessibilityItem
 

docs/advanced_topics/images/image_file_formats.md

@@ -26,6 +26,7 @@ image formats and let the browser choose the one it prefers. For example:
 ```
 
 (customising_output_formats)=
+
 ### Customising output formats
 
 By default, all `avif`, `bmp` and `webp` images are converted to the `png` format

docs/releases/6.3.md

@@ -125,7 +125,6 @@ This feature was developed by Bart Cieliński, alexkiro, and Sage Abdullah.
  * Add an example of customizing a default accessibility check (Cynthia Kiser)
  * Demonstrate access protection with `TokenAuthentication` in the [Wagtail API v2 Configuration Guide](/advanced_topics/api/v2/configuration) (Krzysztof Jeziorny)
 
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 ### Maintenance
 
  * Removed support for Python 3.8 (Matt Westcott)
@@ -152,7 +151,6 @@ This feature was developed by Bart Cieliński, alexkiro, and Sage Abdullah.
  * Improve code reuse for footer actions markup across generic views (Sage Abdullah)
  * Deprecate internal `DeleteMenuItem` API for footer actions (Sage Abdullah)
 
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 ## Upgrade considerations - deprecation of old functionality
 
 ### Removed support for Python 3.8