title `404 | XXX` before creating router

[userquin]

Describe the bug

Before creating the router the page title is 404 | XXX, check the screenshot below, it is also reproducible on dev.

Reproduction

Just run pnpm run docs-dev on this repo and check the title.

Expected behavior

The title should not contain the 404.

System Info

System:                                                 
    OS: Windows 10 10.0.19044                             
    CPU: (16) x64 Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz
    Memory: 45.30 GB / 63.95 GB                           
  Binaries:                                               
    Node: 16.13.0 - C:\Program Files\nodejs\node.EXE      
    Yarn: 1.22.17 - C:\Program Files\nodejs\yarn.CMD      
    npm: 8.1.0 - C:\Program Files\nodejs\npm.CMD          
  Browsers:                                               
    Chrome: 99.0.4844.82
    Edge: Spartan (44.19041.1266.0), Chromium (99.0.1150.55)
    Internet Explorer: 11.0.19041.1566
  npmPackages:
    vitepress: ^0.22.3 => 0.22.3

Additional context

Validations

• Follow our Code of Conduct
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.