fix dead links

Author: yyx990803

src/guide/best-practices/security.md

@@ -184,4 +184,4 @@ HTTP security vulnerabilities, such as cross-site request forgery (CSRF/XSRF) an
 
 ## Server-Side Rendering (SSR)
 
-There are some additional security concerns when using SSR, so make sure to follow the best practices outlined throughout [our SSR documentation](/guide/extras/ssr.html) to avoid vulnerabilities.
+There are some additional security concerns when using SSR, so make sure to follow the best practices outlined throughout [our SSR documentation](/guide/scaling-up/ssr.html) to avoid vulnerabilities.

src/guide/extras/ways-of-using-vue.md

@@ -31,7 +31,7 @@ SPAs typically require the backend to expose API endpoints - but you can also pa
 
 Pure client-side SPAs are problematic when the app is sensitive to SEO and time-to-content. This is because the browser will receive a largely empty HTML page, and has to wait until the JavaScript is loaded before rendering anything.
 
-Vue provides first-class APIs to "render" a Vue app into HTML strings on the server. This allows the server to send back already-rendered HTML, allowing end users to see the content immediately while the JavaScript is being downloaded. Vue will then "hydrate" the application on the client side to make it interactive. This is called [Server-Side Rendering (SSR)](/guide/extras/ssr) and it greatly improves Core Web Vital metrics such as [Largest Contentful Paint (LCP)](https://web.dev/lcp/).
+Vue provides first-class APIs to "render" a Vue app into HTML strings on the server. This allows the server to send back already-rendered HTML, allowing end users to see the content immediately while the JavaScript is being downloaded. Vue will then "hydrate" the application on the client side to make it interactive. This is called [Server-Side Rendering (SSR)](/guide/scaling-up/ssr) and it greatly improves Core Web Vital metrics such as [Largest Contentful Paint (LCP)](https://web.dev/lcp/).
 
 There are higher-level Vue-based frameworks built on top of this paradigm, such as [NuxtJS](https://v3.nuxtjs.org/), which allow you to develop a fullstack application using Vue and JavaScript.
 

src/guide/reusability/composables.md

@@ -275,7 +275,7 @@ Mouse position is at: {{ mouse.x }}, {{ mouse.y }}
 
 It is OK to perform side effects (e.g. adding DOM event listeners or fetching data) in composables, but pay attention to the following rules:
 
-- If your are working in an application that utilizes [Server-Side Rendering](/guide/extras/ssr.html) (SSR), make sure to perform DOM-specific side effects in post-mount lifecycle hooks, e.g. `onMounted()`. These hooks are only called in the browser so you can ensure code inside it has access to the DOM.
+- If your are working in an application that utilizes [Server-Side Rendering](/guide/scaling-up/ssr.html) (SSR), make sure to perform DOM-specific side effects in post-mount lifecycle hooks, e.g. `onMounted()`. These hooks are only called in the browser so you can ensure code inside it has access to the DOM.
 
 - Make sure to clean up side effects in `onUnmounted()`. For example, if a composable sets up a DOM event listener, it should remove that listener in `onUnmounted()` (as we have seen in the `useMouse()` example). It can also be a good idea to use a composable that automatically does this for you, like the `useEventListener()` example.
 

src/guide/scaling-up/ssr.md

@@ -28,4 +28,4 @@ Properly configuring all the discussed aspects of a production-ready server-rend
 
 - A build command that bundles your code with [Rollup](https://rollupjs.org/), pre-configured to output highly optimized static assets for production.
 
-Vite also provides built-in [support for server-side rendering](https://vitejs.d](/guide/extras/ssr.html). You can find an example project with Vue [here](https://github.com/vitejs/vite/tree/main/packages/playground/ssr-vue)
+Vite also provides built-in [support for server-side rendering](https://vitejs.d](/guide/scaling-up/ssr.html). You can find an example project with Vue [here](https://github.com/vitejs/vite/tree/main/packages/playground/ssr-vue)