docs(cli): add mention of default port with experimental-https

Author: samcx

docs/02-app/02-api-reference/06-cli/next.mdx

@@ -207,6 +207,8 @@ For certain use cases like webhooks or authentication, you can use [HTTPS](https
 next dev --experimental-https
 ```
 
+With the generated certificate, the default Next.js development server will exist on `https://localhost:3000` unless a port option is specified with `-p`, `--port`, or `PORT`.
+
 You can also provide a custom certificate and key with `--experimental-https-key` and `--experimental-https-cert`. Optionally, you can provide a custom CA certificate with `--experimental-https-ca` as well.
 
 ```bash filename="Terminal"