docs: remove redundant newlines and indentations (#29190)

docs/1.getting-started/12.upgrade.md

@@ -4,7 +4,6 @@ description: 'Learn how to upgrade to the latest Nuxt version.'
 navigation.icon: i-ph-arrow-circle-up
 ---
 
-
 ## Upgrading Nuxt
 
 ### Latest release
@@ -445,7 +444,7 @@ We have already proactively migrated the public Nuxt modules which we are aware
 
 However, if you are a module author using the `builder:watch` hook and wishing to remain backwards/forwards compatible, you can use the following code to ensure that your code works the same in both Nuxt v3 and Nuxt v4:
 
- ```diff
+```diff
 + import { relative, resolve } from 'node:fs'
   // ...
   nuxt.hook('builder:watch', async (event, path) => {

docs/1.getting-started/3.configuration.md

@@ -4,7 +4,6 @@ description: Nuxt is configured with sensible defaults to make you productive.
 navigation.icon: i-ph-gear
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-
 By default, Nuxt is configured to cover most use cases. The [`nuxt.config.ts`](/docs/guide/directory-structure/nuxt-config) file can override or extend this default configuration.
 
 ## Nuxt Configuration