路由 （Routes）就是决定应用如何根据URL向用户展示相应的内容。
SvelteKit使用基于 文件系统 的路由，也就说代码中的文件组织形式直接关系到其对应的访问URL。
每个src/routes下的+page.svelte的文件，就是一个页面. 当前只有src/routes/+page.svelte对应/. 如果我们使用/about访问就会报404页面找不到错误.
小主可以通过添加src/routes/about/+page.svelte文件修复这个问题：

SvelteKit uses filesystem-based routing, which means that the routes of your app — in other words, what the app should do when a user navigates to a particular URL — are defined by the directories in your codebase. Every +page.svelte file inside src/routes creates a page in your app. In this app we currently have one page — src/routes/+page.svelte, which maps to /. If we navigate to /about, we’ll see a 404 Not Found error.

Let’s fix that. Add a second page, src/routes/about/+page.svelte, copy the contents of src/routes/+page.svelte, and update it:

<nav>
	<a href="/">home</a>
	<a href="/about">about</a>
</nav>

<h1>about</h1>
<p>this is the about page.</p>

现在小主就可以使用/和/about访问了

We can now navigate between / and /about.

与传统的多页应用不同，导航到 /about 并返回会像单页应用一样更新当前页面的内容。这让我们兼顾了两者的优势——快速的服务器渲染启动和即时导航。（此行为可以配置。）

Unlike traditional multi-page apps, navigating to /about and back updates the contents of the current page, like a single-page app. This gives us the best of both worlds — fast server-rendered startup, then instant navigation. (This behaviour can be configured.)