Clean whitespace formatting in docs

- Update formatting with prettier in the documentation

docs/advanced_topics/customisation/admin_templates.md

@@ -121,6 +121,7 @@ There are two ways to customise Wagtail’s colour scheme:
 For static colours, either set each colour separately (for example `--w-color-primary: #2E1F5E;`); or separately set [HSL](https://en.wikipedia.org/wiki/HSL_and_HSV) (`--w-color-primary-hue`, `--w-color-primary-saturation`, `--w-color-primary-lightness`) variables so all shades are customised at once. For example, setting `--w-color-secondary-hue: 180;` will customise all of the secondary shades at once.
 
 ```{include} ../../_static/wagtail_colors_tables.txt
+
 ```
 
 ## Specifying a site or page in the branding

docs/reference/hooks.md

@@ -458,8 +458,6 @@ def editor_css():
 The `insert_editor_css` hook is deprecated and will be removed in a future release. We recommend using [](insert_global_admin_css) instead.
 ```
 
-
-
 (insert_global_admin_css)=
 
 ### `insert_global_admin_css`