Sync kit docs (sveltejs#984)

sync kit docs

Co-authored-by: Rich-Harris <1162160+Rich-Harris@users.noreply.github.com>

Author: github-actions[bot]

Diff for: apps/svelte.dev/content/docs/kit/20-core-concepts/10-routing.md

@@ -170,7 +170,7 @@ To create a layout that applies to every page, make a file called `src/routes/+l
 ...but we can add whatever markup, styles and behaviour we want. The only requirement is that the component includes a `@render` tag for the page content. For example, let's add a nav bar:
 
 ```svelte
-<!---- file: src/routes/+layout.svelte --->
+<!--- file: src/routes/+layout.svelte --->
 <script>
 	let { children } = $props();
 </script>

Diff for: apps/svelte.dev/content/docs/kit/40-best-practices/03-auth.md

@@ -19,6 +19,6 @@ Auth [cookies](@sveltejs-kit#Cookies) can be checked inside [server hooks](hooks
 
 ## Guides
 
-[Lucia](https://lucia-next.pages.dev/) is a reference for session-based web app auth. It contains example code snippets and projects for implementing session-based auth within SvelteKit and other JS projects. You can add code which follows the Lucia guide to your project with `npx sv create` when creating a new project or `npx sv add lucia` for an existing project.
+[Lucia](https://lucia-auth.com/) is a reference for session-based web app auth. It contains example code snippets and projects for implementing session-based auth within SvelteKit and other JS projects. You can add code which follows the Lucia guide to your project with `npx sv create` when creating a new project or `npx sv add lucia` for an existing project.
 
-An auth system is tightly coupled to a web framework because most of the code lies in validating user input, handling errors, and directing users to the appropriate next page. As a result, many of the generic JS auth libraries include one or more web frameworks within them. For this reason, many users will find it preferrable to follow a SvelteKit-specific guide such as the examples found in [Lucia](https://lucia-next.pages.dev/) rather than having multiple web frameworks inside their project.
+An auth system is tightly coupled to a web framework because most of the code lies in validating user input, handling errors, and directing users to the appropriate next page. As a result, many of the generic JS auth libraries include one or more web frameworks within them. For this reason, many users will find it preferrable to follow a SvelteKit-specific guide such as the examples found in [Lucia](https://lucia-auth.com/) rather than having multiple web frameworks inside their project.

Diff for: apps/svelte.dev/content/docs/kit/98-reference/10-@sveltejs-kit.md

@@ -133,9 +133,7 @@ Checks whether this is an action failure thrown by `fail`.
 <div class="ts-block">
 
 ```dts
-function isActionFailure(
-	e: unknown
-): e is ActionFailure<undefined>;
+function isActionFailure(e: unknown): e is ActionFailure;
 ```
 
 </div>