Note about urls in upgrade docs

docs/source/Setup/Installation-Upgrade.md

@@ -1,6 +1,6 @@
 # Upgrading an existing installation
 
-## Evennia v0.9.5 to  1.0
+## Evennia v0.9.5 to 1.0
 
 Prior to 1.0, all Evennia installs were [Git-installs](./Installation-Git.md). These instructions
 assume that you have a cloned `evennia` repo and use a virtualenv (best practices).
@@ -30,8 +30,11 @@ game dir, continue below.
 anything you want to keep), you can _delete_ it entirely.
 - Copy `evennia/evennia/game_template/web` to `mygame/` (e.g. using `cp -Rf` or a file manager). This new `web` folder
 replaces the old one and has a very different structure.
-- `evennia migrate`
-- `evennia start`
+- It's possible you need to replace/comment out import and calls to the deprecated
+[`django.conf.urls`](https://docs.djangoproject.com/en/3.2/ref/urls/#url). The new way to call it is
+[available here](https://docs.djangoproject.com/en/4.0/ref/urls/#django.urls.re_path).
+- Run `evennia migrate`
+- Run `evennia start`
 
 If you made extensive work in your game dir, you may well find that you need to do some (hopefully minor)
 changes to your code before it will start with Evennia 1.0. Some important points: