Add comment on slash normalizing in server (#39653)

Documentation / Examples

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Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

packages/next/server/base-server.ts

@@ -423,6 +423,10 @@ export default abstract class Server<ServerOptions extends Options = Options> {
       const urlParts = (req.url || '').split('?')
       const urlNoQuery = urlParts[0]
 
+      // this normalizes repeated slashes in the path e.g. hello//world ->
+      // hello/world or backslashes to forward slashes, this does not
+      // handle trailing slash as that is handled the same as a next.config.js
+      // redirect
       if (urlNoQuery?.match(/(\\|\/\/)/)) {
         const cleanUrl = normalizeRepeatedSlashes(req.url!)
         res.redirect(cleanUrl, 308).body(cleanUrl).send()