fix: remove `configureServer()` hack and use Vite 3 instead

src/node/plugin.ts

@@ -162,7 +162,6 @@ export function createVitePressPlugin(
       // serve our index.html after vite history fallback
       return () => {
         server.middlewares.use((req, res, next) => {
-          if (req.url!.endsWith('.html')) {
           res.statusCode = 200
           res.setHeader('Content-Type', 'text/html')
           res.end(`
@@ -179,9 +178,6 @@ export function createVitePressPlugin(
     <script type="module" src="/@fs/${APP_PATH}/index.js"></script>
   </body>
 </html>`)
-            return
-          }
-          next()
         })
       }
     },